Hilltopping influences spatial dynamics in a patchy population of tiger moths.

Dispersal is a key driver of spatial population dynamics. Dispersal behaviour may be shaped by many factors, such as mate-finding, the spatial distribution of resources, or wind and currents, yet most models of spatial dynamics assume random dispersal. We examined the spatial dynamics of a day-flying moth species (Arctia virginalis) that forms mating aggregations on hilltops (hilltopping) based on long-term adult and larval population censuses. Using time-series models, we compared spatial population dynamics resulting from empirically founded hilltop-based connectivity indices and modelled the interactive effects of temperature, precipitation and density dependence. Model comparisons supported hilltop-based connectivity metrics including hilltop elevation over random connectivity, suggesting an effect of hilltopping behaviour on dynamics. We also found strong interactive effects of temperature and precipitation on dynamics. Simulations based on fitted time-series models showed lower patch occupancy and regional synchrony, and higher colonization and extinction rates when hilltopping was included, with potential implications for the probability of persistence of the patch network. Overall, our results show the potential for dispersal behaviour to have important effects on spatial population dynamics and persistence, and we advocate the inclusion of such non-random dispersal in metapopulation models.

Influence of delayed density and ultraviolet radiation on caterpillar baculovirus infection and mortality.

Infectious disease is an important potential driver of population cycles but must occur through delayed density-dependent infection and resulting fitness effects. Delayed density-dependent infection by baculoviruses can be caused by environmental persistence of viral occlusion bodies (OBs), which can be influenced by environmental factors. Specifically, ultraviolet radiation is potentially important in reducing the environmental persistence of viruses by inactivating OBs. Delayed density-dependent viral infection has rarely been observed empirically at the population level although theory predicts that it is necessary for pathogens to drive population cycles. Similarly, field studies have not examined the effects of ultraviolet radiation on viral infection rates in natural animal populations. We tested if viral infection is delayed density-dependent with the potential to drive cyclic dynamics and if ultraviolet radiation influences viral infection levels. We censused 18 Ranchman's tiger moth (Arctia virginalis) populations across 9° of latitude over 2 years and quantified the effects of direct and delayed density and ultraviolet radiation on proportion infected by baculovirus, infection severity and survival to adulthood. Caterpillars were collected from field populations and reared in the laboratory. Baculovirus has not previously been described infecting A. virginalis, and we used genetic methods to confirm the identity of the virus. We found that proportion infected, infection severity and survival to adulthood exhibited delayed density dependence. Ultraviolet radiation in the previous summer decreased infection severity, which increased caterpillar survival probability. Structural equation modelling indicated that the effect of lagged density on caterpillar survival was mediated through proportion infected and infection severity and was 2.5-fold stronger than the indirect effect of ultraviolet. We successfully amplified polh, lef-8 and lef-9 viral genes from caterpillars, and BLAST results confirmed that the virus was a nucleopolyhedrovirus. Our findings provide clear evidence that delayed density-dependent mortality can arise through viral infection rate and severity in insects, which supports the role of viral disease as a mechanism, among others, that may drive insect population cycles. Furthermore, our findings support predictions that ultraviolet radiation can modify viral disease dynamics in insect populations, most likely through attenuating viral persistence in the environment.

Changes in quantity, spending, and nutritional characteristics of adult, adolescent and child urban corner store purchases after an environmental intervention.

OBJECTIVES: The purpose of this study was to assess one-year changes in corner store purchases (nutritional characteristics, amount spent) of children, adolescents, and adults in a low-income urban environment before and after implementing an environmental intervention to increase the availability of healthier products. METHODS: Corner store owners were provided tools (trainings, signage, refrigeration) to increase the promotion and availability of several healthy foods. Based on the degree of support provided, stores were classified as "basic" or "high-intensity" intervention stores. Data on purchases and their nutrient content were gathered (n = 8671 at baseline, n = 5949 at follow-up) through customer purchase assessment interviews and direct observation outside of 192 corner stores in Philadelphia from March 2011 to August 2012. RESULTS: At baseline, shoppers spent $2.81 ± 3.52 for 643 ± 1065 kcal. Energy, select nutrients, and the total amount spent did not significantly change in the overall sample from baseline to follow-up. Similarly, there was no effect on energy and nutrient content when comparing changes over time between basic and high-intensity stores. CONCLUSIONS: There were no significant changes in the energy or nutrient content of corner store purchases one year after implementation of environmental changes to increase the availability of healthier products.

Spatial habitat heterogeneity influences host-pathogen dynamics in a patchy population of Ranchman's tiger moth.

Host-pathogen dynamics are influenced by many factors that vary locally, but models of disease rarely consider dynamics across spatially heterogeneous environments. In addition, theory predicts that dispersal will influence host-pathogen dynamics of populations that are linked, although this has not been examined empirically in natural systems. We examined the spatial dynamics of a patchy population of tiger moths and its baculovirus pathogen, in which habitat type and weather influence dynamics. Theoretical models of host-baculovirus dynamics predict that such variation in dynamics between habitat types could be driven by a range of factors, of which we predict two are likely to be operating in this system: (1) differences in the environmental persistence of pathogens or (2) differences in host intrinsic rates of increase. We used time series models and monitored infection rates of hosts to characterize population and disease dynamics and distinguish between these possibilities. We also examined the role of host dispersal (connectivity) and weather as important contributors to dynamics, using time series models and experiments. We found that the population growth rate was higher, delayed density dependence was weaker, and long-period oscillations had lower amplitudes in high-quality habitat patches. The infection rate was higher on average in high-quality habitat, and this was likely to have been driven by higher mean population densities and no differences in pathogen persistence in different habitats (delayed density dependence). Time series modeling and experiments also showed an interactive effect of temperature and precipitation on moth population growth rates (likely caused by variation in host plant quality and quantity), and an effect of connectivity. Our results showed that spatial heterogeneity, connectivity, climate, and their interactions were important in driving host-baculovirus dynamics. In particular, our study found that connected patches and spatial heterogeneity generated differences in dynamics that only partially aligned with theoretical predictions.

Effects of experimental watering but not warming on herbivory vary across a gradient of precipitation.

Climate change can affect biotic interactions, and the impacts of climate on biotic interactions may vary across climate gradients. Climate affects biotic interactions through multiple drivers, although few studies have investigated multiple climate drivers in experiments. We examined the effects of experimental watering, warming, and predator access on leaf water content and herbivory rates of woolly bear caterpillars (Arctia virginalis) on a native perennial plant, pacific silverweed (Argentina anserina ssp. pacifica), at two sites across a gradient of precipitation in coastal California. Based on theory, we predicted that watering should increase herbivory at the drier end of the gradient, predation should decrease herbivory, and watering and warming should have positive interacting effects on herbivory. Consistent with our predictions, we found that watering only increased herbivory under drier conditions. However, watering increased leaf water content at both wetter and drier sites. Warming increased herbivory irrespective of local climate and did not interact with watering. Predation did not affect herbivory rates. Given predictions that the study locales will become warmer and drier with climate change, our results suggest that the effects of future warming and drying on herbivory may counteract each other in drier regions of the range of Argentina anserina. Our findings suggest a useful role for range-limit theory and the stress-gradient hypothesis in predicting climate change effects on herbivory across stress gradients. Specifically, if climate change decreases stress, herbivory may increase, and vice versa for increasing stress. In addition, our work supports previous suggestions that multiple climate drivers are likely to have dampening effects on biotic interactions due to effects in different directions, though this is context-dependent.

Sand Dollar Larvae Show Within-Population Variation in Their Settlement Induction by Turbulence.

Settlement-the generally irreversible transition from a planktonic phase to a benthic phase-is a critical stage in the life history of many shoreline organisms. It is reasonable to expect that larvae are under intense selection pressure to identify appropriate settlement habitat. Several decades of studies have focused mainly on local indicators that larvae use to identify suitable habitat, such as olfactory cues that indicate the presence of conspecifics or a favored food source. Our recent work has shown that the larvae of seashore-dwelling echinoids (sea urchins, sand dollars, and kin) can be primed to settle following a brief exposure to a broader-scale indicator of their approach to shore: an increase in fluid turbulence. Here we demonstrate that this priming shows within-population variation: the offspring of certain Pacific sand dollar (Dendraster excentricus) parents-both specific fathers and specific mothers, regardless of the other parent-are more responsive to turbulence than others. In particular, the observation of the effect correlating, in some cases, with specific fathers leads us to conclude that these behavioral differences are likely genetic and thus heritable. We also report that turbulence exposure causes larvae to temporarily sink to the bottom of a container of seawater and that larvae that respond in this way are also more likely to subsequently settle. We hypothesize a two-step scenario for the evolution of turbulence responsiveness at settlement and suggest that the evolutionary origin of these behaviors could be a driving force for population differentiation and speciation.

Síntomas Osteomusculares y factores Individuales presentes En Los trabajadores de la bodega De En Una empresa de La Industria textil En Barranquilla / Osteomuscular Symptomsand Individual Factors Present in the Workers of the Warehouse of a Textile Industry Company in Barranquilla

Introducción: El síntoma osteomuscular se puedepresentar en cualquier momento de la vida ya que son algo inmanente al ser humano; sin embargo,estas molestias pueden aumentarse y permanecer pormás tiempo en el individuo debido a múltiples factores individuales. Objetivo: Determinar los síntomas osteomusculares y factores individuales presentes en los trabajadores de la bodega de unaempresa de industria textil en Barranquilla en el periodo comprendido de febrero a diciembre, 2017.Metodología: El método que se utilizo fue deductivo, con una población de 21 trabajadores en el año 2017. Se recolectaron datos socio-demográficos (sexo, edad y tiempo en el cargo) y factores individuales (IMC). Los síntomas osteomusculares fueron evaluados por mediode una encuestade síntomas y factores individuales. Resultados:Se observó que el 47,6% de la población presenta sobrepesoy el 19% restante se encuentra en obesidad tipo 1, Se destaca que el 66,66% de los trabajadores encuestados, tienen problemas con su peso. la población estudio se identificó que las edades prevalentes están 85,7% representa por edad adulta, mayores de 26 años y el 14,3% son jóvenes menores a 26 años. Conclusión: A partir de lo mencionado y evidenciado anteriormente escrito se encontróque la frecuencia de los síntomas es baja y prevalece la respuesta casi nunca o nunca. Síntomas específicos como Dolor de cabeza, cuello, muñeca izquierda, abdomen, lumbar y pierna derecha, son los que más variabilidad presentan en cuanto a su frecuencia.En general los trabajadores refieren que lleven un estilo de vida saludable, no fuman, ni consumen bebidas alcohólicas, duermen más de 6 horas diarias y no tienen antecedentes de cáncer. Se observó en particular que el 57,14% consume café diariamente, mientras que el 42,86% no consume café. El 19,05% manifiesta llevar hábitos de vida sedentarios

Introduction: Osteomuscularsymptoms can occur at any time in life since they are something immanent to the human being; however, these discomforts can be increased and remain longer in the individual due to multiple individual factors.Objective:To determine the osteomuscular symptoms and individual factors present in the workers of the winery of a textile industry company in Barranquilla in the period from February to December, 2017. Methodology:The method I used was deductive, with a population of 21 workers in 2017. Socio-demographic data (sex, age and time in office) and individual factors (BMI) were collected. Osteomuscular symptoms were evaluated by means of a survey of syphilis and individual factors.Results:It was observed that 47.6% of the population is overweight and the remaining 19% is in type 1 obesity. It is noted that 66.66% of the workers surveyed have problems with their weight. The study population identified that the prevailing ages are 85.7% represented by adult age, older than 26 years and 14.3% are younger than 26 years.Conclusions:From the aforementioned and evidenced previously written it was found that the frequency of symptoms is low and the answer prevails almost never or never. Specific symptoms such as headache, neck, left wrist, abdomen, lumbar and right leg are the most variable in their frequency. In general, workers report that they lead a healthy lifestyle, do not smoke, or consume alcoholic beverages, sleep more than 6 hours a day, and do not have a history of cancer. It was observed in particular that 57.14% consume coffee daily, while 42.86% do not consume coffee. 19.05% manifest sedentary lifestyle habits

Manipulación del pescado fresco a bordo de embarcaciones de media altura de la isla de Margarita, estado Nueva Esparta (Venezuela) / Fresh fish handling on board half-height fishing ships of Margarita island, Nueva Esparta state (Venezuela)

Disminuir la temperatura del pescado no garantiza una mejor calidad, a no ser que desde su captura hasta el consumidor final sea manipulado de acuerdo a normas higiénicas. La presente revisión tiene por objetivo compilar la información reseñada en trabajos de grado y otros de divulgación restringida, sobre la manipulación del pescado fresco a bordo de embarcaciones de media altura, en Isla de Margarita (Venezuela). Estas embarcaciones utilizan el palangre fondero para pescar lo que permite que los ejemplares lleguen vivos. Se reportaron las siguientes situaciones: Es común observar que los tripulantes lancen bruscamente los pescados durante su clasificación; en la etapa de evisceración, restos de sangre y vísceras se dejan en baldes o sobre cubierta, en contacto directo con otros pescados; no se vigila que el lavado posterior elimine completamente vísceras o sangre. Por otra parte, bodegas presentaban señales de suciedad, corrosión y superficies no lisas. La temperatura del aire de estos locales era de 2,3 °C en horas matutinas y de 2,8 °C en la tarde. En ocasiones, al estibar los pescados en bodega, no se rodeaban de hielo y eran dejados sobre la capa superior de hielo y en contacto de unos con otros. Solo cuando se rodeaban de hielo, la temperatura les descendía a 0°C. Por último, durante el desembarco se exponían a mayores temperaturas (10°C) y algunos se colocaban directamente sobre el piso de los peñeros recibidores. Se concluye que las deficiencias higiénico-sanitarias detectadas pudieran incidir en la calidad y en la inocuidad del pescado.

Lowering the temperature of fish does not assure a better quality, unless its handling from the time of catch to the time it is consumed is in accordance with hygienic norms. The present review’ s objective is to compile information described in grade papers and other references of limited disclosure, about the handling of fresh fish on board half-height fishing ships in Margarita Island (Venezuela). These boats use deep longline as fishing gear which allows specimens to reach the boats while still alive. The following conditions are reported: It is normally noted that crew members throw the fish with brusqueness during their classification; in the stripping step, blood and viscera leftovers are placed directly on board or inside buckets in direct contact with other fish; there is no supervision to make sure that the subsequent washing removes completely viscera and blood. On the other hand, holds had marks of dirtiness, corrosion and uneven surfaces. The air’s temperature in holds was 2.3 °C during morning hours and of 2.8 °C in the evening. Sometimes, when stowing, the fish were not surrounded with ice and were just placed over the superior layer of ice in contact of one with the others. Only when the fish are surrounded with ice, the temperature descended to 0 °C. Finally, during the unloading, fish are exposed to higher temperatures (10 °C) and some specimens are placed directly on the floor of the receiving little ships. It is concluded that the detected insufficiency in hygienic-sanitary measures could influence the quality and safety of fish.