Leaf-cutter ants serve as keystone species that affect and advance diversity, productivity, and nutrient flow in tropical habitats. Field work was conducted in Costa Rica between May and June 2017 to investigate the role of environmental factors on biomass transport by leaf-cutter ants. Thirty leaf-cutter ant trails were identified along hiking paths throughout La Selva Biological Station, and measures corresponding to foraging efficiency (i.e. speed of biomass transport, average mass of forage transported, trail workforce composition, and biomass transport rate) were documented, along with potential environmental determinants of foraging efficiency (e.g. time of day, precipitation, canopy cover, proximity to forage source and colony). Multiple linear regression models indicated that time of day was significantly associated with workforce composition, weight of forage transported, speed of transport, and biomass transport rate. Precipitation was associated with workforce composition, weight of forage transported, and biomass transport rate. Substrate type was associated with speed of transport and biomass transport rate. Forage source proximity was associated with workforce composition, while proximity to colony was associated with weight of forage transported. Biomass transport rate was also associated with canopy cover. This study characterizes key features of the foraging ecology of leaf-cutter ants, and demonstrates how foraging efficiency is affected by environmental factors.

Bergen Community College (BCC) soils were used to generate mud suspensions to construct microbial fuel cells (MFCs) with the anode buried with the mud, while the cathode rested on top. MFCs incubated at 37°C showed more electrical output and electrogenic bacteria than those grown at 25°C. The most productive MFC generated a maximum of 80 microwatts with 1.67 × 10⁹ electrogenic microorganisms. 16S rRNA clone libraries were developed and analyzed using next generation sequencing. The average soil bacterial community was comprised of 17 different bacterial phyla. The most abundant bacterial phyla in soils were Actinobacteria (33.76%), Proteobacteria (25.60%), Chloroflexi (9.70%), Acidobacteria (8.98%), and Planctomycetes (6.10%). The 16S rRNA genes of the biofilm grown on the anode of the most efficient MFCs were amplified and cloned to determine the composition and diversity of electrogenic bacteria. The average bacterial community was comprised of 21 bacterial phyla. The most abundant bacterial phyla in MFCs were Firmicutes (18.98%), Proteobacteria (18.79%), Actinobacteria (13.63%), Chloroflexi (11.43%), and Planctomycetes (7.91%). All MFCs showing electricity generation had an increase in Firmicutes sequences at all taxonomical levels. The MFC lacking large numbers of Firmicutes did not show electrogenic bacteria nor any electrical production. Bacteria belonging to the phylum Firmicutes provided an important contribution to the development of diverse, stable, and sustainable electrogenic bacterial communities.

The widespread use of endocrine disrupting chemicals (EDCs) has been a source of concern because of their various effects on the endocrine system. These effects include metabolic disorders, complications in reproductive health, hormone-related cancers, and neurodevelopmental disorders. Of particular concern is bisphenol A (BPA), a synthetic compound commonly found in consumer products such as water bottles, thermal receipt paper, and epoxy resins used in processed food packaging. Previous studies have shown that BPA can mimic estrogen through a variety of mechanisms and thus elicit an endocrine response. Some manufacturers have responded by removing BPA from their products; however, studies using a replacement compound bisphenol S have reported it to be just as, if not more, dangerous. The use of zebrafish (Danio rerio) larvae as a model organism allows for the effects of bisphenol exposure to be rapidly quantified through a simple behavioral assay. In studies involving bisphenol exposure, the use of zebrafish has demonstrated reproductive, developmental, endocrine, and behavioral effects. The study of bisphenol F, yet another endocrine disruptor that has become a replacement for BPA in consumer products, is highly important to public safety.

For any animal, learning to distinguish between very similar spatial cues in the environment is a fundamental skill to acquire, because it can ultimately lead to a live or die situation. However, it is cognitively demanding to learn to discriminate between very similar spatial environments (as opposed to distinct ones). Spatial pattern separation is the cognitive process that keeps similar, overlapping memories distinct, and is thought to underlie many spatial tasks used in behavioral studies. In captivity, it has been shown that environmental enrichment can lead to enhanced spatial learning in fish, however, a task that utilizes spatial pattern separation has never been conducted on fish. In the current study, we used the delayed non-matching to place Radial Arm Maze (RAM) to determine if there were differences in spatial pattern separation in zebrafish (Danio rerio) housed with or without enrichment. In the delayed non-matching to place RAM, the animal has to discriminate between low spatially separated stimuli (near, similar) and high spatially separated stimuli (far, distinct). Our results show that environmental enrichment enhanced spatial learning at both low and high separation (i.e. at both spatially similar and distinct maze locations). Thus, enrichment did not selectively enhance zebrafish learning only at spatially similar cues as we expected, but rather zebrafish housed with enrichment were better learners overall. Given the growing use of zebrafish as a research model for behavioral research, these data will help us to understand how different housing and rearing methods influence spatial learning in captive lab fish, and ultimately will help to inform welfare guidelines on best practices for housing fish in captivity.

Skin and soft tissue infections (SSTIs) and methicillin-resistant Staphylococcus aureus (MRSA) are becoming increasingly prevalent in the healthcare field. Certain traditional medicines have been shown to have antibacterial properties. This study aims to identify medicinal plants with antibacterial properties against SSTI-associated bacteria and MRSA, and identify the specific antibacterial compounds within each extract. Five plant extracts were examined: burdock (Arctium minus), mullein (Verbascum thapsus), red clover (Trifolium pretense), yarrow (Achillea millefolium), and bilberry (Vaccinium myrtillas). The extracts were examined for antibacterial effects against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Streptococcus pneumoniae, Enterococcus saccharolyticus, and MRSA. Mullein and red clover extracts were the most effective, inhibiting five of seven bacteria, including MRSA. Growth of the highly resistant bacterium was inhibited by mullein extract and red clover extract. The compounds identified by gas chromatography-mass spectrometry (GC-MS) within red clover and mullein with antibacterial properties were ethyl linolenate and ethyl-α-d-glucopyranoside, respectively. This is the first initial screening study to identify mullein and red clover extract as potential topical antibacterial agents against MRSA, which suggests that further study is needed.

The red knot, Calidris canutus, is a species of migratory shorebird that is currently listed as “near threatened” on the IUCN Red List; the subspecies Calidris canutus rufa is listed as a “threatened” species under the US Endangered Species Act. Causes of red knot population decline have not been clearly identified. Here I hypothesize that snow coverage declines in the high Arctic may be linked to red knot breeding success and to population declines in Florida. In this study, wavelet and crosswavelet analyses were used to identify temporal trends and relationships between changes in red knot populations and Arctic snow coverage. Strong El Niño Southern Oscillation events that occurred during the late 1970s through the 1980s appear to have contributed to a decline in snow cover, which was linked to the significant decline in the red knot population. The period of highest common power was predominated by antiphase trending, suggesting that red knot populations mirror snow coverage trends from 1982 to 1988, a period of maximum population decline.

Birds are endotherms with a unique thermoneutral zone, a temperature range where metabolic requirements are relatively consistent but increase dramatically when temperatures fall below the lower threshold. As the popularity of human-supplied bird feeders increases, so too does the need for a greater understanding of the effects of abiotic factors on the feeding behavior of wintering birds at these supplemental food sources. The main purpose of this study was to evaluate whether the level of bird activity at supplementary feeding stations increased with decreasing temperature to compensate for the increase in metabolic activity. To evaluate this, bird feeders were weighed at a supplementary feeding station over a period of six weeks and the level of bird activity was observed for an allotted time. To determine whether the trend in temperature and other abiotic factors was significant, a linear regression analysis was utilized for various measures of bird activity. There was no significant trend between temperature and bird activity. Two measures of bird activity and wind did show a significant positive correlation, however. It was concluded that the main reason the study did not demonstrate data supporting previous literature and the posited hypothesis was due to the lack of extremely low temperature days. The mild temperatures throughout the study failed to fall below the lower threshold, which did not necessitate an increase in feeding behavior to compensate for thermoregulation.

Gout, one of the most prevalent forms of inflammatory arthritis, is characterized by severe joint pain that often interferes with or prevents daily activities. Much has been done to elucidate the causes, treatment, and prevention of gout. We know that gout typically forms due to the buildup of monosodium urate crystals in the joints due to high levels of serum uric acid. Effective treatments, in the form of urate lowering drugs, have been well established. Research has demonstrated that diets low in purine nucleotides can help prevent gout attacks. New treatment and prevention strategies are currently being developed that could change the way we look at gout in the near future. The purpose of this review is to summarize our current knowledge of this disease and highlight some recent advances in the field.