Cohort antler size signals environmental stress in a moderate climate

Research in northern latitudes confirms that climate teleconnections exert important influences on ungulate fitness, but studies from regions with milder climates are lacking. We explored the influence of the Pacific Decadal Oscillation (PDO), Northern Atlantic Oscillation (NAO), and El Niño-Southern Oscillation (ENSO) on male, 2.5-year-old white-tailed deer (Odocoileus virginianus) antler and body mass in Mississippi, USA, a region with mild winters and warm, humid summers. Explanatory variables were seasonal averages of each climate index extending back to 3 years prior to account for possible maternal and lag effects. Seasonal climate indices from the period of gestation and the first year of life were correlated with deer morphometrics. Reduced antler mass was largely correlated (R² = 0.52) with PDO values indicating dry conditions during parturition and neonatal development and NAO values indicating warmer than normal winters during gestation and the first year of life. Body mass was less correlated (R² = 0.16) to climate indices, responding negatively to warmer winter weather during the first winter of life. Climate may promote variable fitness among cohorts through long-term effects on male competition for dominance and breeding access. Because broad-scale climate indices simplify complex weather systems, they may benefit management at larger scales. Although this study compared climate with morphological variables, it is likely that demographic characteristics can likewise be modeled using climate indices. As climate change in this region is projected to include greater variability in summer precipitation, we may see concomitantly greater variability in fitness among cohorts of white-tailed deer.

Latitude and daily-weather effects on gobbling activity of wild turkeys in Mississippi

Weather has been recognized as a density independent factor influencing the abundance, distribution, and behavior of vertebrates. Male wild turkeys' (Meleagris gallopavo) breeding behavior includes vocalizations and courtship displays to attract females, the phenology of which can vary with latitude. State biologists design spring turkey-hunting season frameworks centered on annual vocalization patterns to maximize hunter engagement. The Mississippi Department of Wildlife, Fisheries, and Parks has traditionally instituted a statewide, 7-week, spring harvest season. However, hunters routinely argue that different peaks in gobbling activity across the state exist. The objective of this study was to determine whether differences in peak gobbling activity existed across a latitudinal gradient of Mississippi and assess the effect of weather on gobbling. During 2008 and 2009, we conducted a statewide gobbling survey. We used generalized additive mixed models to describe the probability and frequency of gobbling activity within northern and southern regions of the state. We also investigated the effect of daily weather conditions on gobbling activity. Our results revealed an approximate 10-14-day difference in peak gobbling activity between southern and northern Mississippi. The majority of all gobbling activity occurred within the current spring harvest framework. Perhaps more importantly, gobbling activity was more prevalent on days of regionally dry conditions (i.e., less humid) according to the Spatial Synoptic Classification. Our results provide information on gobbling activity phenology relative to hunting-season dates and weather-response information. Our approach may be particularly applicable in states with relatively shorter seasons or highly variable daily weather conditions that moderate gobbling frequency.

Crisis support-seeking behavior and temperature in the United States: Is there an association in young adults and adolescents?

BACKGROUND

Mounting evidence demonstrates the relationship between high temperatures and adverse mental health outcomes. Yet, no study has examined the influence of temperature on crisis support-seeking behavior among youth in large urban areas.

METHODS

Crisis Text Line (CTL) is a text messaging service that provides crisis interventions for support-seeking individuals for a range of mental-health outcomes in the United States. We applied a distributed lag non-linear modeling technique to assess the short-term impacts of daily maximum and minimum temperature on crisis-related events in four metropolitan locations in the USA.

RESULTS

There were multiple positive associations in three of the four study locations that demonstrate crisis help-seeking behavior increased during anomalously warm conditions.

CONCLUSIONS

This study suggests that there is a significant association between high minimum or maximum temperatures and crisis help-seeking behaviors in young adults and adolescents in urban areas in the United States.

Heat/mortality sensitivities in Los Angeles during winter: a unique phenomenon in the United States

BACKGROUND

Extreme heat is often associated with elevated levels of human mortality, particularly across the mid-latitudes. Los Angeles, CA exhibits a unique, highly variable winter climate, with brief periods of intense heat caused by downsloping winds commonly known as Santa Ana winds. The goal is to determine if Los Angeles County is susceptible to heat-related mortality during the winter season. This is the first study to specifically evaluate heat-related mortality during the winter for a U.S. city.

METHODS

Utilizing the Spatial Synoptic Classification system in Los Angeles County from 1979 through 2010, we first relate daily human mortality to synoptic air mass type during the winter season (December, January, February) using Welch's t-tests. However, this methodology is only somewhat effective at controlling for important inter- and intra-annual trends in human mortality unrelated to heat such as influenza outbreaks. As a result, we use distributed lag nonlinear modeling (DLNM) to evaluate if the relative risk of human mortality increases during higher temperatures in Los Angeles, as the DLNM is more effective at controlling for variability at multiple temporal scales within the human mortality dataset.

RESULTS

Significantly higher human mortality is uncovered in winter when dry tropical air is present in Los Angeles, particularly among those 65 years and older (p < 0.001). The DLNM reveals the relative risk of human mortality increases when above average temperatures are present. Results are especially pronounced for maximum and mean temperatures, along with total mortality and those 65 + .

CONCLUSIONS

The discovery of heat-related mortality in winter is a unique finding in the United States, and we recommend stakeholders consider warning and intervention techniques to mitigate the role of winter heat on human health in the County.

Where are weather-suicide associations valid? An examination of nine US counties with varying seasonality

There has been much research on the associations between weather variables and suicide rates. However, the state of understanding has remained rather stagnant due to many contradictory findings. The purpose of this project is to examine a larger database of suicides that includes a longer and more recent period of record (1975-2010) across numerous locations in the USA. In all, we examine nine total counties (and the primary city associated with them) with a special effort made to compare locations with varying degrees of temperature seasonality: Cook (Chicago), Fulton (Atlanta), King (Seattle), Los Angeles (Los Angeles), Maricopa (Phoenix), Miami-Dade (Miami), Philadelphia (Philadelphia), Salt Lake (Salt Lake City), and St. Louis (St. Louis). We first examine the unique seasonal cycle in suicides evident in each locale and then use distributed lag nonlinear modeling (DLNM) to relate the suicide data to daily surface temperatures. Results suggest that a late spring/summer peak generally exists in suicide rates, and above average temperatures are associated with increased suicide risk in almost all study counties. Further, it appears that these associations can be found in both mid-latitude and sub-tropical climate types.

The structure and mechanics of Moso bamboo material

Although bamboo has been used structurally for millennia, there is currently increasing interest in the development of renewable and sustainable structural bamboo products (SBPs). These SBPs are analogous to wood products such as plywood, oriented strand board and glue-laminated wood. In this study, the properties of natural Moso bamboo (Phyllostachys pubescens) are investigated to further enable the processing and design of SBPs. The radial and longitudinal density gradients in bamboo give rise to variations in the mechanical properties. Here, we measure the flexural properties of Moso bamboo in the axial direction, along with the compressive strengths in the axial and transverse directions. Based on the microstructural variations (observed with scanning electron microscopy) and extrapolated solid cell wall properties of bamboo, we develop models, which describe the experimental results well. Compared to common North American construction woods loaded along the axial direction, Moso bamboo is approximately as stiff and substantially stronger, in both flexure and compression but denser. This work contributes to critical knowledge surrounding the microstructure and mechanical properties of bamboo, which are vital to the engineering and design of sustainable SBPs.

Association of weekly suicide rates with temperature anomalies in two different climate types

Annual suicide deaths outnumber the total deaths from homicide and war combined. Suicide is a complex behavioral endpoint, and a simple cause-and-effect model seems highly unlikely, but relationships with weather could yield important insight into the biopsychosocial mechanisms involved in suicide deaths. This study has been designed to test for a relationship between air temperature and suicide frequency that is consistent enough to offer some predictive abilities. Weekly suicide death totals and anomalies from Toronto, Ontario, Canada (1986-2009) and Jackson, Mississippi, USA (1980-2006) are analyzed for relationships by using temperature anomaly data and a distributed lag nonlinear model. For both analysis methods, anomalously cool weeks show low probabilities of experiencing high-end suicide totals while warmer weeks are more likely to experience high-end suicide totals. This result is consistent for Toronto and Jackson. Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide.

The energy-water nexus: are there tradeoffs between residential energy and water consumption in arid cities?

Water scarcity, energy consumption, and air temperature regulation are three critical resource and environmental challenges linked to urban population growth. While appliance efficiency continues to increase, today's homes are larger and residents are using more energy-consuming devices. Recent research has often described the energy-water nexus as a "tradeoff" between energy and water due to reduced temperatures resulting from irrigated vegetation. Accordingly, some arid cities have implemented landscape-conversion programs that encourage homeowners to convert their yards from grass (mesic) to drought-tolerant (xeric) landscapes to help conserve water resources. We investigated these relationships in Phoenix, Arizona by examining energy and water data for the summer months of June-September 2005 while temperature variability was analyzed from a local heat wave. Results show parallel consumption patterns with energy and water use strongly correlated and newer homes using more of both. The counterintuitive findings show that "drought-resistant" models may not be beneficial for community health, environment, or economics and that this issue is further complicated by socio-economic variables.

A glossary for biometeorology

Here we present, for the first time, a glossary of biometeorological terms. The glossary aims to address the need for a reliable source of biometeorological definitions, thereby facilitating communication and mutual understanding in this rapidly expanding field. A total of 171 terms are defined, with reference to 234 citations. It is anticipated that the glossary will be revisited in coming years, updating terms and adding new terms, as appropriate. The glossary is intended to provide a useful resource to the biometeorology community, and to this end, readers are encouraged to contact the lead author to suggest additional terms for inclusion in later versions of the glossary as a result of new and emerging developments in the field.

Effects of temperature variation on suicide in five U.S. counties, 1991-2001

Effects of weather variables on suicide are well-documented, but there is still little consistency among the results of most studies. Nevertheless, most studies show a peak in suicides during the spring season, and this is often attributed to increased temperatures. The purpose of this study is to test the relationship between monthly temperature and monthly suicide, independent of months or seasons, for five counties located across the United States. Harmonic analysis shows that four of the five counties display some seasonal components in the suicide data. However, simple linear regression shows no correlation between suicide and temperature, and discriminant analysis shows that monthly departure from mean annual suicide rates is not a useful tool for identifying months with temperatures that are colder or warmer than the annual average. Therefore, it appears that the seasonality of suicides is due to factors other than temperature.

Postnatal development of retinal projections in the brushtailed possum, Trichosurus vulpecula

The postnatal development of retinal projections was studied in the brushtailed possum, Trichosurus vulpecula. [3H]proline was injected into one eye of 13 young possums aged 24-84 days in order to trace retinal pathways. The dorsal lateral geniculate nucleus (LGNd) can be identified in Nissl material at 19 days but not at 9-10 days. By 40 days some cytoarchitectural lamination of the LGNd is apparent and by 71 days the adult pattern of cell layers is present. At 24 days retinal fibers occupy by lateral part of the LGNd on both sides of the brain. By 38-40 days the retinal fibers fill be contralateral LGNd and the binocular part of the ipsilateral LGNd and there is a beginning of the segregation of retinal fibers into left and right eye territories. By 49-50 days a partial segregation is achieved, and complete segregation by 71 days. At 9-10 days the superior colliculus is not differentiated into layers and there is a thick zone of cell proliferation around the ventricle. By 23 days the superior colliculus has well-defined cell layers and there is still some indication of cell proliferation around the ventricle. By 40 days, the superior colliculus shows little evidence of cell proliferation. At 24 days retinal fibers fill the superficial layers of the contralateral optic tectum and are lightly distributed through the superficial layers of the rostral half of the ipsilateral tectum. By 38 days the ipsilateral retinal input is restricted to the deeper layers of the tectum. These results show that the adult pattern of retinal projections to the LGNd and optic tectum develops a number of weeks before eye opening occurs (at 90-120 days).

Properties of the ribosomes of antibiotic producers: effects thiostrepton and micrococcin on the organisms which produce them

Ribosomes of Streptomyces azureus, which produces thiostrepton, are resistant to thiostrepton by virtue of being unable to bind the antibiotic. These ribosomes are also resistant to a number of other antibiotics (the thiostrepton group) which may share a common ribosomal binding site and a common mode of action with thiostrepton. Conversely, Bacillus pumilis and a strain of micrococcus, which produce the (probably identical) antibiotics micrococcin P and micrococcin, respectively, possess ribosomes which are susceptible to these antibiotics in vitro, although the organisms themselves are resistant.