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This study investigated the temperature of pigs’ blood as it flowed from the sticking wound at exsanguination using infra-red thermometry and how it might reflect changes in core body temperature. A total of 417 pigs were monitored over a three-day period, which included a subset of 206 pigs for which additional information concerning transport conditions and ambient temperature was also known. The range of blood temperatures recorded was large (35.6-43.2°C) with a significant number of the animals found to have blood temperatures above the pigs’ normal temperature (39 ± l°C). Within the subset of pigs, average blood temperature of all the pigs in a pen at slaughter appeared to be related to pen temperatures and position on the lorry and was sensitive enough to detect changes in environmental ambient conditions.
The relative costs and benefits of thermal acclimation for manipulating field performance of pest insects depend upon a number of factors including which traits are affected and how persistent any trait changes are in different environments. By assessing plastic trait responses of Ceratitis capitata (Mediterranean fruit fly) across three distinct operational environments (laboratory, semi-field, and field), we examined the influence of different thermal acclimation regimes (cool, intermediate [or handling control], and warm) on thermal tolerance traits (chill-coma recovery, heat-knockdown time, critical thermal minimum and critical thermal maximum) and flight performance (mark-release-recapture). Under laboratory conditions, thermal acclimation altered thermal limits in a relatively predictable manner and there was a generally positive effect across all traits assessed, although some traits responded more strongly. By contrast, dispersal-related performance yielded strongly contrasting results depending on the specific operational environment assessed. In semi-field conditions, warm- or cold-acclimated flies were recaptured more often than the control group at cooler ambient conditions suggesting an overall stimulatory influence of thermal variability on low-temperature dispersal. Under field conditions, a different pattern was identified: colder flies were recaptured more in warmer field conditions relative to other treatment groups. This study highlights the trait- and context-specific nature of how thermal acclimation influences traits of thermal performance and tolerance. Consequently, laboratory and semi-field assessments of dispersal may not provide results that extend into the field setting despite the apparent continuum of environmental complexity among them (laboratory < semi-field < field).
Environmental conditions surrounding herbicide applications are known to affect weed control and crop response. Variable levels of rice injury caused by florpyrauxifen-benzyl have been observed across cropping systems and environmental conditions, warranting research in which single environmental and management strategies are isolated to understand the effect of each factor on rice injury and subsequent reductions in rice growth. A field study was conducted to determine the effects of planting date, rice cultivar, and florpyrauxifen-benzyl rate on rice injury, maturity, and yield. Two greenhouse studies were conducted to determine the effect of soil moisture and time of flooding after florpyrauxifen-benzyl application on rice injury caused by the herbicide. Growth chamber experiments were conducted to isolate the effects of temperature and light intensity on rice injury caused by florpyrauxifen-benzyl. In the field study, levels of injury varied across planting dates in both years, indicating the influence of environment on the crop response to florpyrauxifen-benzyl applications. Under dry (40% soil moisture) and saturated (100%) soil conditions, rice injury increased to 36% and 35%, respectively, compared with 27% and 25% injury at 60% and 80% soil moisture, respectively. Flooding rice 0 to 6 d after florpyrauxifen-benzyl application reduced visible injury; however, a reduction in rice tiller production occurred when the rice was flooded the same day as application. Visible rice injury increased when florpyrauxifen-benzyl was applied under low light intensity (700 µmol m−2 s−1) and high temperatures (35/24 C day/night). Based on these findings, applications of florpyrauxifen-benzyl are least likely to cause unacceptable rice injury when applied to soils having 60% and 80% saturation in high light, low temperature environments, and the crop is flooded 3 to 6 d following application.
Social inequality is ubiquitous in contemporary human societies, and has deleterious social and ecological impacts. However, the factors that shape the emergence and maintenance of inequality remain widely debated. Here we conduct a global analysis of pathways to inequality by comparing 408 non-industrial societies in the anthropological record (described largely between 1860 and 1960) that vary in degree of inequality. We apply structural equation modelling to open-access environmental and ethnographic data and explore two alternative models varying in the links among factors proposed by prior literature, including environmental conditions, resource intensification, wealth transmission, population size and a well-documented form of inequality: social class hierarchies. We found support for a model in which the probability of social class hierarchies is associated directly with increases in population size, the propensity to use intensive agriculture and domesticated large mammals, unigeniture inheritance of real property and hereditary political succession. We suggest that influence of environmental variables on inequality is mediated by measures of resource intensification, which, in turn, may influence inequality directly or indirectly via effects on wealth transmission variables. Overall, we conclude that in our analysis a complex network of effects are associated with social class hierarchies.
Host-associated microbiomes are ubiquitous in nature, but highly variable in both space and time, and shaped by a diverse range of biotic and abiotic factors. This chapter summarises the numerous drivers of variation in microbiome structure and function across both plants and animals. Plants harbour distinct microbial communities in their rhizosphere, phyllosphere and endosphere. These communities interact with hosts in a different way, and in turn are shaped by a unique set of environmental factors. For example, the rhizosphere supports a particularly diverse microbial community shaped by plant exudates and signalling molecules to facilitate nutrient transfer to the host. Similarly, variation in animal microbiomes is driven by host genetic, life-history and environmental traits, including phylogeny, diet, age, metabolism and sociality. Several of these factors are also given more detailed treatment in later chapters. Particular attention is given to our current state of knowledge concerning initial colonisation and subsequent succession in microbial community composition in juveniles, the consequences of which remain one of the major outstanding questions in microbiome research.
The aim of this Research Reflection is to describe the basic rumen function of goats and its modification in response to environmental factors, as well as to discuss similarities and differences when compared to other ruminants. In so doing we shall reveal the adaptive capacity of goats to harsh environments. The basic rumen function in goats is similar to other species of ruminants, as stressed by the opportunity to apply the updates of feeding systems for ruminants to goats. The rumen epithelium acts as a protective barrier between the rumen and the host, but it can be damaged by toxic compounds or acidosis. The rumen also plays an important role in water balance, both for dehydration and rehydration. Recent studies show that the microbiota exhibits a high fractional stability due to functional redundancy and resilience, but this needs more investigation. The microbial community structure differs between goats and cows, which explains the difference in sensitivity to milk fat depression following intake of high lipid diets. Goats also differ from other ruminants by their enhanced ability to feed-sort, but as with cows they can suffer from acidosis. Nevertheless, goats can be considered to be very resistant to environmental factors such as water stress, salt stress or heat stress, and this is especially so in some endogenous breeds. They also are able to detoxify tannins, polyphenols and other secondary metabolites. Some new trials involving feeding behaviour, microbiota and omics or approaches by meta-analyses or modelling will improve our knowledge of rumen function in goats.
Huisache is a major brush problem on native rangelands and pastures in South Texas. Although herbicide applications to foliage provide very high plant-kill levels, the same herbicides have not proven reliable when applied as broadcast ground or aerial foliar treatments. Aerial and ground broadcast herbicide foliar treatments were applied to 31 huisache sites. Soil temperature and soil moisture were measured at a depth of 30 cm at the time of herbicide application. Cumulative rainfall before herbicide application was recorded. Across all aerial treatments, plant mortality was 69% for plants shorter than 2 m versus 40% for plants taller than 2 m. Across all aerial- and ground-treated sites, plants shorter than 2 m had an average 89% mortality when cumulative 2-wk rainfall was at least 50 mm, versus 72% mortality with cumulative rainfall less than 50 mm. Average plant mortality was 84% when 4-wk cumulative rainfall was at least 76 mm, versus 71% with rainfall less than 76 mm; and 85% when, on a dry-to-wet scale of 0 to 10, soil moisture measured at least 8, versus 71% when soil moisture measured less than 8. In a separate aerial trial, plant-mortality effects of spray droplet size (417, 630, and 800 µm) and spray volume (37.4 L ha−1 and 93.5 L ha−1) were replicated and tested at a single study site in 2014. Plant mortality was lowest for the 93.5 L ha−1 and 800 µm treatment. Plant mortality rates for other treatments were similar, demonstrating a greater importance of droplet size than spray volume. Targeting huisache trees shorter than 2 m, when cumulative rainfall has reached at least 50 mm or at least 76 mm 2 or 4 wk before application, respectively, as well as maintaining spray droplet sizes no larger than 630 µm can increase herbicide efficacy with foliar broadcast applications.
The objective of the current study was to evaluate the effects of sugarcane and maize silage mixture v. maize silage in diets of Holstein cows and investigate performance under two environmental conditions. The cows were placed in freestalls, with individuals and stalls assigned to one of four treatments according to a replicated 4 × 4 Latin square design with 20-day periods divided into 11 days of adaptation (wash-out period) and 9 days of collection. Treatments were arranged in a 2 × 2 × 2 factorial design: total diets (maize silage (MS-based diet), the roughage mixture (RM-based diet, sugarcane : maize silage, 500 : 500 g/kg DM) plus concentrate); environmental conditions (with (W) and without (Wo) fan and nebulizers); and measurement times (09.40 and 14.00 h). The temperature and relative humidity was higher at 14.00 h and contributed to increased temperature-humidity index (76.6, W v. 75.9, Wo). Feed dry matter intake (DMI) was similar between diets (20.2 kg/day), but milk production and feed efficiency were lower with RM. Under W conditions, higher fat content and total solids of milk were observed with the RM-based diet, while crude protein and lactose were higher with MS. The Wo conditions increased body surface temperature (BS) in cows fed MS. The rectal temperature (RT) was higher with RM. The BS, RT and respiratory rate were higher at 14.00 h (34.9, 38.6 °C and 58.2 breaths/min) than at 09.40 h. The RM-based diet maintained DMI and milk composition, but not milk production. The use of the cooling system led to higher DMI and feed N efficiency use.
Differences in fruit morphology among or within species might indicate differences in other regenerative traits, such as seed dormancy and germination. In species with physical dormancy (PY), environmental conditions are suggested to be responsible for dormancy break in field. Seeds of Vachellia caven have PY. This species exhibits two fruit morphs highly represented in Córdoba forests, Argentina: one is dehiscent and the other is indehiscent. In this study we performed a burial experiment with the aim to determine if the differences in V. caven fruit morphology were related to different patterns of PY break of their seeds in field conditions. We related these patterns to (1) environmental conditions that could influence the loss of PY, and (2) histological features of the lens zone. Seeds of both morphs exhibited dormancy break within 14 months of the start of the experiment, but with different patterns. The dehiscent morph showed an abrupt percentage of seeds that broke dormancy 14 months after the beginning of the experiment, probably after undergoing environmental changes similar to those suggested by the two-stage softening model. The indehiscent morph showed a gradual increase in seeds that broke dormancy, not clearly related to any of the environmental variables studied. No differences in seed coat structure of the lens zone were observed between morphs. The existence of both morphs could confer the species with higher possibilities of establishing and coping with environmental heterogeneity. Those characteristics contribute to the understanding of the success of this species in open and disturbed environments.
Chlorite (C)-corrensite (Co)-smectite (S) seriesminerals occur as vein constituents in the two epithermal ore veins, the Chuetsu and Shuetsu veins of the Todoroki Au-Ag deposit. The characteristics of the C–Co–S seriesminerals indicate that the clays may be products of direct precipitation from hydrothermal fluids and subsequent mineralogical transformations during and/or after vein formation. The minerals from the Chuetsu vein are characterized by ‘monomineralic’ corrensite showing an extensive distribution throughout the vein, and trioctahedral smectite occurring locally. The Shuetsu vein minerals are characterized by C-Co series minerals which can be divided into three different types: a I type including discrete chlorite with minor amounts of S layers, a II type comprising interstratified C/Co and discrete chlorite, and a III type characterized by segregation structures of C and Co layers. The C-Co series minerals show slightly different spatial distributions in the Shuetsu vein. Different epithermal environments during the vein formations and possible kinetic effects may have played a role in the formation and conversion of Co-C series at the Shuetsu vein and S-Co series at the Chuetsu vein.
Ragweed parthenium is a highly invasive weed species in several countries, including Australia. Laboratory experiments were conducted to evaluate the effect of temperature, light, salinity, pH, and moisture on germination of two Australian biotypes of ragweed parthenium: Clermont (highly invasive) and Toogoolawah (noninvasive). Although seeds of both biotypes could germinate under complete darkness, germination was improved by 20% to 49% under a 12-h photoperiod. Both biotypes germinated over a wide range of constant (8 to 35 C), and alternating day/night (15/5 to 35/25 C) temperatures. However, the Clermont biotype exhibited significantly higher germination than Toogoolawah biotype over the range of temperatures studied. Highest germination of Clermont (100%) and Toogoolawah (97%) was observed at constant temperatures of 14 to 23 C and 23 C, respectively. The best alternating day/night temperature for germination of both biotypes was 25/15 C. Clermont also germinated better than Toogoolawah under osmotic- and salt-stress conditions. Osmotic stress had moderate negative effects on germination, with 52% and 36% of the Clermont and Toogoolawah seeds able to germinate at −0.60 MPa, respectively. Complete germination inhibition for both biotypes was observed at an osmotic potential of −1.2 MPa. Both biotypes also germinated at a very high sodium chloride (NaCl) concentration of 250 mM. A 50% reduction in germination of Toogoolawah and Clermont was caused by 99 and 154 mM NaCl, respectively. Germination of the Clermont biotype was not affected by a wide range of pH (4.0 to 10.0), whereas the strong acidic and alkaline pH levels (4.0 and 10.0) caused 18% and 25% reductions in germination of the Toogoolawah biotype compared with control. The Clermont biotype had a higher ability to germinate across all treatments compared with the Toogoolawah biotype, which might be a contributing factor toward the high invasive ability of the former compared with the latter.
This study aimed to examine the influence of feed delivery frequency and environmental conditions on daily time budget of lactating dairy cows. The study was carried out in two commercial dairy farms with Holstein herds. Fifty lactating dairy cows milked in automatic milking units (AMS farm) and 96 primiparous lactating dairy cows milked in a conventional milking parlour (conventional farm) were exposed to different frequencies of feed delivery replicated in different periods of the year (warm and mild) that were characterized by different temperature-humidity indices (THI). On each farm, feeding treatments consisted of two different feed delivery frequencies (1× and 2× on the AMS farm; 2× and 3× on the conventional farm). All behaviours of the cows were monitored for the last 8 d of each treatment period using continuous video recording. The two data sets from different farm systems were considered separately for analysis. On both farms, environmental conditions expressed as THI affected time budgets and the pattern of the behavioural indices throughout the day. The variation in the frequency of feed delivery seems to affect the cow's time budget only in a limited way. Standing time of cows on the conventional farm and the time spent by cows in the milking waiting area on the AMS farm both increased in response to increased feeding frequency. Although feed delivery frequency showed limited influence on cow's time budget, the effect on standing time could be carefully considered, especially on farms equipped with AMS where the type of cow traffic system (e.g., milking first) might amplify the negative consequences of more frequent feed delivery. Further investigations are required to evaluate the effect of THI and feed delivery frequency on other aspects of behavioural activity.
Growth chamber experiments were conducted to determine the effects of soil temperature on the response of corn to imazaquin soil residues. In a silt loam soil, 24/30 C (night/day) or 18/24 C soil temperatures caused greater inhibition of shoot growth than 12/18 C soil temperature. However, in a sandy loam soil, inhibition of corn shoot growth was maximal at 18/24 C, and there was no difference in shoot-growth inhibition between the lowest and highest temperatures. Higher soil temperatures caused greater root-growth inhibition in the sandy loam soil but not in silt loam soil. Soil temperature did not affect 14C-imazaquin uptake from either soil. Higher soil temperatures increased the translocation of imazaquin from root to shoot tissue in both soils. In the sandy loam soil, imazaquin metabolism in root tissue decreased as soil temperature increased, with twice as much parent herbicide recovered from roots of plants grown under the highest compared with the lowest temperature treatments. Soil temperature had no effect on imazaquin metabolism in shoot tissue. Longer-term experiments (22 d) were conducted with the sandy loam soil to determine the effect of changes in air temperature on corn response to imazaquin soil residues. Plants exposed to 24/30 C for 7 or 14 d of the final 14-d growing period showed greater inhibition of shoot growth compared with plants maintained at 12/18 C. Uptake and translocation of 14C-imazaquin to shoots was greater in plants maintained at 24/30 C throughout the final 14-d period than in plants maintained at 12/18 C. Plants grown for 7 d at 24/30 C during the final 14-d period either preceding or following 7 d growth at 12/18 C showed increased translocation of imazaquin to shoots but no difference in imazaquin uptake compared with plants maintained at 12/18 C. Neither air nor soil temperature treatments had any effect on imazaquin concentration in soil water.
Field studies were conducted from 2000 to 2002 to determine whether glyphosate applied during periods of low temperature (< 10 C) provides effective control of garlic mustard without injury to nontarget native herbs. A 1% glyphosate solution was applied on three dates between November and March in 2000 to 2001 and 2001 to 2002, when average daily temperatures ranged from −4.2 to 7 C. Glyphosate reduced the population density of prereproductive springtime garlic mustard infestations, regardless of application timing. During the primary bolting period (April to June), mortality of garlic mustard rosettes in sprayed plots was 87 to 94%, whereas mortality in nontreated plots was 12% in the first year and 41% in the second. Nontarget native herbaceous species were not injured by the cold-weather herbicide applications and exhibited higher springtime densities than in the nontreated plots. By targeting garlic mustard rosettes during the part of the year when most other plant species are dormant, managers can selectively control garlic mustard without damage to native herbs and, thereby, increase forest restoration success.
Field studies were conducted in Indiana, Michigan, Ohio, and Wisconsin in 1992 and 1993 to evaluate growth and response of common ragweed (Ambrosia artemisiifolia) to imazethapyr. Plants from ecotypes originating in each state were grown at all four locations. Nontreated plants grown in Wisconsin or Ohio were consistently taller than plants grown in Michigan or Indiana, regardless of the origin of the seeds. Nontreated plants originating from Wisconsin or Michigan showed a trend toward flowering earlier than those originating from Indiana or Ohio, regardless of test site. The results suggest the existence of common ragweed ecotypes based on origin of the seeds. Weather conditions after treatment with imazethapyr had a greater influence on common ragweed control and regrowth than the origin of common ragweed seeds. Common ragweed regrew following imazethapyr application through the development of axillary buds under conditions of warm temperatures and moist soils during the 4 to 6 wk following imazethapyr application. Mild to cool temperatures or dry conditions following imazethapyr application reduced treated common ragweed regrowth. Both early- and mid-postemergence imazethapyr treatments delayed flowering of all ecotypes. However, flowering of imazethapyr-treated plants followed the same order as nontreated plants, with plants from the Michigan or Wisconsin ecotypes showing a trend toward flowering earlier than those from Indiana or Ohio.
Field studies were conducted in 1998 and 1999 to evaluate the efficacy of glufosinate on Palmer amaranth, redroot pigweed, and common waterhemp at different growth stages in soybean planted at early, normal, and late dates. At 2, 4, and 8 wk after treatment, common waterhemp control was greater than Palmer amaranth and redroot pigweed control with single glufosinate applications of 410 g ai/ha at 2- to 5-, 7- to 10-, or 15- to 18-cm Amaranthus height or with two sequential applications of 293 g/ha at 2- to 5-cm height and 2 wk later. Only the sequential applications of 410 and 293 g/ha resulted in more than 80% control of Palmer amaranth and redroot pigweed, but all five treatments controlled common waterhemp more than 80%. All glufosinate treatments reduced the dry weight of all Amaranthus species by more than 65%. However, the sequential applications resulted in the greatest dry weight reductions.
Sequential feeding (SF) consists of splitting energy (E) and protein/calcium (P) fractions temporally, improving the feed conversion ratio (FCR) of hens compared with a continuous distribution during the day. In a previous study, the E fraction (with a low level of protein) was provided in the morning, whereas the P fraction (with low level of energy) was given in the afternoon. However, there is no clear evidence that a requirement in energy or proteins is connected to these distribution sequences, whereas the requirement for calcium is known to be required in the afternoon. To evaluate the effects on performances of the modulation of energy and protein supplies in SF, five different sequential treatments were offered: E0P0/E0P0; E+P+/E−P−; E+P−/E−P+; E0P+/E0P− and E+P0/E−P0 where E+ represents a high energy level, E0 a moderate one and E− a low one (with the same meaning for P regarding protein supply). Afternoon fractions were provided with particulate calcium. A total of 168 Hendrix hens were housed in individual cages from 20 to 39 weeks of age in two environmentally contrasted rooms. Feed intake in the morning and afternoon fractions, egg production, egg weight, BW and weight of digestive organs were recorded. No diet effect was observed concerning feed intake, egg production and BW. These results suggested that hens are not able to fit their feed intake on energy or protein level of fractions within half-day duration, whereas at the day scale same protein and energy intakes were observed. Moreover, the time of nutrient distribution in feeding did not seem to have an impact on birds’ performances. These studies have also demonstrated that, despite strong environmental pressure, the hens with SF had attenuated performance but continue to produce eggs.
We used aquatic macro-invertebrates as a model to investigate the relationship between the regional species richness (RSR) and local species richness (LSR) in Peninsular Malaysia. A total of 38 streams (local scale) in seven catchments (regional scale), were sampled for aquatic macro-invertebrates. Eleven environmental variables (i.e. pH, DO, velocity, temperature, width, depth, TSS, BOD, COD, ammonia and canopy cover) were measured to assess their importance for local species richness. The average species richness was 34.9 species per region and the average abundance was 1380 individual per region. The highest number of species was 41, while the lowest species richness was 31. We applied local-regional richness regression models to explore the nature of the RSR–LSR relationship and then used variation partitioning to determine the relative importance of RSR and environmental conditions on LSR. We found a linear RSR–LSR relationship, which indicates unsaturated communities for macro-invertebrates in Malaysian streams and absence of local control with strong effects of regional processes. Variation in LSR explained by RSR was 43%, while the variation fraction in LSR explained by environmental conditions was low (2%) and not significant. We conclude that the variation in LSR is mainly controlled by the regional diversity pool (i.e. RSR) for aquatic macro-invertebrates in Peninsular Malaysia. However, weak effects of environmental conditions may reflect relatively low variability in the habitat among investigated streams. Further studies at larger scales, and involving different regions in this area, will be useful to draw comprehensive conclusions about determinants of local species diversity for stream invertebrates.
This study investigates a phytophylous community of Chironomidae larvae on the submerged plant species Myriophyllum spicatum L. in a eutrophic lake (Lake Sakadaš, Danube floodplain area in Croatia) during summer 2004. This macrophyte species appeared for the first time in the lake in 2004, lasted approximately three months and was considered as a temporary habitat. The chironomid community was very abundant in the stands of this macrophyte species, which developed at three sites. The recorded species belong to three subfamilies: Chironominae (Chironomini and Tanytarsini), Orthocladiinae and Tanypodinae. Species composition varied in time, though Orthocladiinae with their representative Cricotopus sylvestris gr. dominated throughout the entire sampling period, accounting for approx. 60% of the total community. However, the presence of this species group experienced a marked drop to only 10% in September when Chironomini larvulae and Paratanytarsus sp. prevailed. Furthermore, the share of Endochironomus albipennis (Meigen 1830) in relation to other species was also consistently higher. NMDS ordination and cluster analysis separated three main colonization periods based on larval abundance. RDA analysis indicated the influence of environmental variables, especially Secchi depth, macrophyte dry weight, depth and water temperature, on chironomid community structure.
An experiment was conducted to determine the rate and maximum percentage of sporulation of Eimeria acervulina oocysts at various environmental conditions relating to temperature (21 versus 33 °C) and relative humidity (RH) (40 versus 80%). Measurements were made during 44 h after excretion of oocysts in 3 substrates: dry litter, clammy litter and pure faeces respectively. Maximum sporulation percentage in both dry (22·6%) and clammy litter (19·5%) was higher (P < 0·005) than in pure faeces (11·6%). Neither temperature nor RH had a significant influence on percentage of oocysts that sporulated. Under these simulated practical conditions approximately 25% of all oocysts sporulated, whereas sporulation under optimal conditions (29 °C, aeration, 2% K2Cr2O7) showed a higher (68%) sporulation ability of oocysts. At 33 °C sporulation proceeded at a faster pace than at 21 °C (P < 0·005). With respect to RH and substrate, once sporulation started, the rate of increase to maximum percentage was not different. Time of onset of sporulation was influenced by temperature (P < 0·0001) and RH (P < 0·001). Time of onset occurred 15 h later at 21 °C compared with 33 °C and 5 h later at 40% RH compared with 80%. Also, an interaction effect (P < 0·01) was found with effect of RH being stronger at 21 °C compared with 33 °C. It was concluded that the most important aspect in the epidemiology of E. acervulina during a flock cycle is the time of onset of sporulation with temperature being the most important factor.