Demographic and life cycle characteristics of montane deer mice

1983 ◽  
Vol 61 (3) ◽  
pp. 574-585 ◽  
Author(s):  
John S. Millar ◽  
Duncan G. L. Innes

Demographic and life cycle characteristics of Peromyscus maniculatus borealis were documented in the wild and in the laboratory. Field studies in the Kananaskis Valley, Alberta, indicated that no mice matured in the summer of their birth, overwintered females produced a maximum of 3 litters each season (average, 1.9), nestling survival was variable (0 to 100%), summer survival of weaned young (average, 0.81/2 weeks) was similar to that of summer adults (average, 0.80/2 weeks), dispersal rates were low, and winter survival (average, 0.98/semimonthly period) was relatively high. These demographic characteristics are similar to those of other populations in which opportunities for reproduction are limited. Laboratory studies indicated that basic life cycle characteristics such as adult size (20.3 g), litter size (5.2), neonate weights (1.70 g), nestling growth rates (0.34 g/day), age at weaning (24.9 days), weight at weaning (9.9 g), and food consumption during lactation (220% of nonbreeding consumption) were not all the same as previously reported for northern P. m. borealis or other Peromyscus. These differences may be related to specific aspects of the annual cycle.

2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.


1991 ◽  
Vol 18 (2) ◽  
pp. 67-71 ◽  
Author(s):  
G. Wehtje ◽  
J. W. Wilcut ◽  
J. A. McGuire ◽  
T. V. Hicks

Abstract Field studies were conducted over a three year period to examine the sensitivity of four peanut (Arachis hypogaea L.) cultivars (Florunner, Sunrunner, Southern runner, and NC 7) to foliar applications of paraquat (1, 1′-dimethyl-4, 4′-bipyridinium ion). Treatments included an untreated control and four herbicide treatments: paraquat applied alone at 0.14 and 0.28 kg/ha, or tank mixed with alachlor [2-chloro-N-(2, 6-diethylphenyl)-N-(methoxymethyl)acetamide] at 4.40 kg/ha. Weeds were hand-removed so that only herbicidal treatments were variables. Paraquat phytotoxicity did not differ between cultivars. No cultivar evaluated was abnormally sensitive nor tolerant to any paraquat-containing treatment. Laboratory studies utilizing radio labelled paraquat revealed that foliar absorption and translocation of paraquat did not vary between peanut cultivars. Yield differences were attributed to differences in yield potential between cultivars.


2009 ◽  
Vol 9 (1) ◽  
pp. 22-31
Author(s):  
Rusli Rustam ◽  
Aunu Rauf ◽  
Nina Maryana ◽  
Pudjianto Pudjianto ◽  
Dadang Dadang

Studies on Leafminer Liriomyza spp. in Green Onion Fields, and Parasitoid Opius chromatomyiae Belokobylskij & Wharton (Hymenoptera: Braconidae).  Field studies were conducted to determine population abundance of leafminers and their parasitoids in green onion fields in Puncak, West Java. In addition to that, laboratory studies were carried out to determine demographic parameter of Opius chromatomyiae as well as response of parasitoid to increasing host density. Results revealed that green onions were infested by two species of leafminers, Liriomyza huidobrensis and Liriomyza chinensis.  Leafminer flies emerged from Erwor leaves (54.5) were significantly higher than those of RP leaves (18.65) (P = 0.0005). However, number of  leafminer flies caught on sticky traps was not statistically different (P = 0.297).  Two species of parasitoid, Hemiptarsenus varicornis and O. chromatomyiae, were associated with leafminers in green onion fields. Higher number of parasitoids emerged from Erwor leaves (13.68) as compared to RP (6.90) (P =0.0007 ). However, level of parasitization were 24.36% on Erwor and 28.45% on RP, and was not significantly different (P = 0.387). Laboratory studies indicated that net reproduction (Ro) of O. chromatomyiae was 28.55, generation time (T) 15.96 days, intrinsic growth rate 0.21, and total of reproductive value 223.64.  The stable age distribution of parasitoid were 37.93% eggs, 24.92% larvae, 20.36% pupae and 16.78% adults.  The parasitoid showed functional response type II to increasing host density, with a = 0.08 and Th = 2.58.


1999 ◽  
Vol 77 (11) ◽  
pp. 1822-1828 ◽  
Author(s):  
Andrew G McAdam ◽  
John S Millar

Growth and female maturation appear to be limited by the availability of dietary protein in natural populations of deer mice (Peromyscus maniculatus borealis) in the Kananaskis Valley, Alberta. We examined the effects of dietary protein content on nestling growth rates and sexual maturation of female deer mice in two laboratory experiments. In the first, mice whose mothers were fed a low-protein mixture of sunflower seeds and oats (14% protein) exhibited slow growth prior to weaning and those fed high-protein cat food (30% protein) postweaning showed compensatory growth. Preweaning but not postweaning diet quality affected the proportion of females who were sexually mature at 42 days of age. Therefore, while deficient nestling growth can be compensated for, the effects of a low-quality maternal diet during lactation may have lasting effects on the maturation of female offspring. In the second experiment, mice raised on isocaloric diets of 14, 20, and 30% protein did not differ in growth as nestlings or juveniles. Differences among the three diets in the proportion of mature females at 42 days did not correspond to dietary protein levels as predicted. Dietary protein content from 14 to 30% appear to be sufficient for juvenile mice raised in captivity.


Behaviour ◽  
2016 ◽  
Vol 153 (13-14) ◽  
pp. 1777-1793 ◽  
Author(s):  
Evan E. Byrnes ◽  
Catarina Vila Pouca ◽  
Sherrie L. Chambers ◽  
Culum Brown

The field of animal personality has received considerable attention in past decades, yet few studies have examined personality in the wild. This study investigated docility, a measure of boldness, in two Port Jackson shark (Heterodontus portusjacksoni) populations using field tests, and if laterality differences explained docility levels. We developed a struggle test as an assay for docility, which is particularly amenable to field studies. The struggle test was effective, and repeatable inter-individual docility differences were observed. Sex, but not population, influenced docility scores, with male sharks being less docile than females. This difference is likely due to the contrasting role each sex plays during mating. We also found individualized lateralization. However, no individual-level relationship between lateralization and docility was detected. Despite reported links between laterality and some personality traits, the relationship between laterality and boldness remains inconclusive in sharks. Further studies will prove essential to clarify the mechanisms behind personality traits in vertebrates.


Soil Research ◽  
2002 ◽  
Vol 40 (7) ◽  
pp. 1095 ◽  
Author(s):  
Guang-Guo Ying ◽  
Rai Kookana

Degradation of a new insecticide/termiticide, fipronil, in a soil was studied in the laboratory and field. Three metabolites of fipronil (desulfinyl, sulfide, and sulfone derivatives) were identified from soils after treatment. Laboratory studies showed that soil moisture content had a great effect on the degradation rate of fipronil and products formed. High soil moisture contents (>50%) favored the formation of a sulfide derivative of fipronil by reduction, whereas low soil moisture (<50%) and well-aerated conditions favored the formation of fipronil sulfone by oxidation. Microorganisms in soil accelerated the degradation of fipronil to sulfide and sulfone derivatives. The third transformation product, a desulfinyl derivative, was formed by photodecomposition of fipronil in water and on the soil surface under sunlight. The desulfinyl derivative degraded rapidly in field soils with a half-life of 41–55 days compared with an average half-life of 132 days for fipronil. The half-life of the 'total toxic component' (fipronil and its metabolites) in field soil was 188 days on average.


2019 ◽  
Vol 93 (23) ◽  
Author(s):  
Chia-Ni Tsai ◽  
Ting-Chun Pan ◽  
Cho-Han Chiang ◽  
Chun-Chiao Yu ◽  
Shih-Han Su ◽  
...  

ABSTRACT The nonstructural protein NS5A of hepatitis C virus (HCV) is a phosphorylated protein that is indispensable for viral replication and assembly. We previously showed that NS5A undergoes sequential serine S232/S235/S238 phosphorylation resulting in NS5A transition from a hypo- to a hyperphosphorylated state. Here, we studied functions of S229 with a newly generated antibody specific to S229 phosphorylation. In contrast to S232, S235, or S238 phosphorylation detected only in the hyperphosphorylated NS5A, S229 phosphorylation was found in both hypo- and hyperphosphorylated NS5A, suggesting that S229 phosphorylation initiates NS5A sequential phosphorylation. Immunoblotting showed an inverse relationship between S229 phosphorylation and S235 phosphorylation. When S235 was phosphorylated as in the wild-type NS5A, the S229 phosphorylation level was low; when S235 could not be phosphorylated as in the S235A mutant NS5A, the S229 phosphorylation level was high. These results suggest an intrinsic feedback regulation between S229 phosphorylation and S235 phosphorylation. It has been known that NS5A distributes in large static and small dynamic intracellular structures and that both structures are required for the HCV life cycle. We found that S229A or S229D mutation was lethal to the virus and that both increased NS5A in large intracellular structures. Similarly, the lethal S235A mutation also increased NS5A in large structures. Likewise, the replication-compromised S235D mutation also increased NS5A in large structures, albeit to a lesser extent. Our data suggest that S229 probably cycles through phosphorylation and dephosphorylation to maintain a delicate balance of NS5A between hypo- and hyperphosphorylated states and the intracellular distribution necessary for the HCV life cycle. IMPORTANCE This study joins our previous efforts to elucidate how NS5A transits between hypo- and hyperphosphorylated states via phosphorylation on a series of highly conserved serine residues. Of the serine residues, serine 229 is the most interesting since phosphorylation-mimicking and phosphorylation-ablating mutations at this serine residue are both lethal. With a new high-quality antibody specific to serine 229 phosphorylation, we concluded that serine 229 must remain wild type so that it can dynamically cycle through phosphorylation and dephosphorylation that govern NS5A between hypo- and hyperphosphorylated states. Both are required for the HCV life cycle. When phosphorylated, serine 229 signals phosphorylation on serine 232 and 235 in a sequential manner, leading NS5A to the hyperphosphorylated state. As serine 235 phosphorylation is reached, serine 229 is dephosphorylated, stopping signal for hyperphosphorylation. This balances NS5A between two phosphorylation states and in intracellular structures that warrant a productive HCV life cycle.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Bradley Ridoutt ◽  
Danielle Baird ◽  
Kimberley Anastasiou ◽  
Gilly Hendrie

AbstractThe food system is responsible for around 70% of global freshwater use. Pathways toward responsible consumption and production of food are therefore critically needed to ensure the planetary boundary for freshwater use is not transgressed. There is also an uneven spatial distribution of freshwater resources and human water demands, meaning that water-scarcity is acute in some regions but a lesser concern in others. Quantifying the water-scarcity impacts associated with food consumption is therefore a complex challenge due to the diversity of individual eating patterns, the very large number of individual food products available, and the many different regions where food is grown or processed. To our knowledge, this is the first study to calculate water footprints for a large number of self-selected diets. Life cycle assessment was used to model the water-scarcity footprints of 9,341 individual Australian adult diets obtained through 24-hour recall as part of the most recent Australian Health Survey. Three water-scarcity indicators were used, including the AWARE model recently developed by a project group working under the auspices of the United Nations Environment Programme (UNEP) / Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative (www.lifecycleinitiative.org). In addition, a diet quality score was calculated for each of these diets. Our objective was to identify pathways toward healthier diets with lower water-scarcity impacts. Dietary water-scarcity footprints averaged 362 L-eq person-1 day-1 and were highly variable (sd. 218 L-eq person-1 day-1), reflecting the diversity of eating habits in the general community. The largest water-scarcity impacts were related to the excessive consumption of discretionary foods (alcoholic beverages, processed meat products, dairy desserts, cream, butter, muesli bars, confectionery, chocolate, biscuits, cakes, waffles, fried potato and extruded snacks, etc.). The potential to reduce dietary water-scarcity impacts is large, although the opportunity to intervene through amended dietary guidelines is not straightforward due to the large variations in water-scarcity footprint intensity between individual foods within a food group, and the inability of consumers to identify lower water-scarcity footprint products without food labeling. Reductions in the water-scarcity footprint of Australian food consumption are likely best achieved through reductions in food waste, technological change to improve water-use efficiency in food production, as well as the implementation of product reformulation and procurement strategies in the food manufacturing sector to avoid higher water-scarcity footprint intensity ingredients.


1999 ◽  
Vol 13 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Zhaohu Li ◽  
Robert H. Walker ◽  
Glenn Wehtje ◽  
H. Gary Hancock

Hypocotyl and root length reduction of soybean (Glycine max) seedlings when seeds were exposed to sulfentrazone during germination were used as indices to classify cultivar response to soil-applied sulfentrazone. Seeds of ‘Stonewall’ (sulfentrazone tolerant) and ‘Asgrow 6785’ (sulfentrazone sensitive) were imbibed and allowed to germinate in 0, 1, 5, 10, and 50 ppm aqueous sulfentrazone solutions for 4 d. Hypocotyl and root lengths were reduced in both cultivars, but the reductions were greater for Asgrow 6785 than for Stonewall. Subsequently, the relative sensitivity of 28 cultivars to sulfentrazone was independently determined by two variations of the hypocotyl reduction method (both conducted in the laboratory) and by traditional full-season field evaluation. Results from laboratory and field studies were in agreement for cultivars distinctly sensitive or tolerant to sulfentrazone. However, cultivars with intermediate tolerance in laboratory studies produced variable responses in the field.


1996 ◽  
Vol 351 (1343) ◽  
pp. 1083-1104 ◽  

Cephalopods, like all other animals, have to decide how to allocate resources; maintenance processes, growth of somatic and reproductive tissues, and locomotor activity all have costs. We should like to be able to identify these costs and discover how efficiently cephalopods make use of the prey that they capture and digest. Cephalopods generally grow fast and mature rapidly; a first task is to determine how accurately laboratory studies reflect growth in the wild, because much of the information we need (such as food conversion efficiencies, excretion rates or the costs of locomotion) can be collected only from animals kept in the laboratory. Comparison of laboratory feeding and growth rates for octopods, sepioids and teuthoids with fisheries data suggests that data collected from cephalopods fed ad libitum in the laboratory may be used validly to construct energy budgets representative of individuals in the wild. The immediate cost of feeding (the specific dynamic action) has been thoroughly documented in Octopus , as has the longer-term elevation or depression of metabolic rate by feeding or starvation; it is assumed that similar costs will be found in squid. The cost of locomotion has been studied in both octopods and squid, but we have only limited data on how much time the animals spend moving, and how rapidly, in the wild. Excretory and faecal losses are assessed from laboratory studies, and maintenance costs estimated from feeding rates that just maintain body mass in the laboratory. Comparison of gross and net food conversion efficiencies suggest that squid convert food into tissues less efficiently than octopods, owing primarily to their greater time spent in locomotion. We present a representative series of energy budgets for octopods (based on Octopus ) and squids (based on Illex and Loligo ), for starving, feeding, migrating and maturing individuals. A major contrast is provided by Nautilus, which lives for ten or twenty years and grows only slowly. Finally we speculate on the possible biochemical and historical factors that may have limited the adaptive radiation of cephalopods, resulting in a group lacking herbivores, detritivores or filter-feeders but extremely successful as carnivores.


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