Ancient and modern DNA track temporal and spatial population dynamics in the European fallow deer since the Eemian interglacial.

Anthropogenic factors have impacted the diversity and evolutionary trajectory of various species. This can be through factors such as pressure on population size or range, habitat fragmentation, or extensive manipulation and translocation. Here we use time-calibrated data to better understand the pattern and processes of evolution in the heavily manipulated European fallow deer (Dama dama). During the Pleistocene, fallow deer had a broad distribution across Europe and were found as far north as Britain during the Eemian interglacial. The last glacial period saw fallow deer retreat to southern refugia and they did not disperse north afterwards. Their recolonisation was mediated by people and, from northern Europe and the British Isles, fallow deer were transported around the world. We use ancient and modern mitochondrial DNA (mtDNA) and mitogenomic data from Eemian Britain to assess the pattern of change in distribution and lineage structure across Europe over time. We find founder effects and mixed lineages in the northern populations, and stability over time for populations in southern Europe. The Eemian sample was most similar to a lineage currently in Italy, suggesting an early establishment of the relevant refuge. We consider the implications for the integration of anthropogenic and natural processes towards a better understanding of the evolution of fallow deer in Europe.

Strong population structure in a species manipulated by humans since the Neolithic: the European fallow deer (Dama dama dama).

Species that have been translocated and otherwise manipulated by humans may show patterns of population structure that reflect those interactions. At the same time, natural processes shape populations, including behavioural characteristics like dispersal potential and breeding system. In Europe, a key factor is the geography and history of climate change through the Pleistocene. During glacial maxima throughout that period, species in Europe with temperate distributions were forced south, becoming distributed among the isolated peninsulas represented by Anatolia, Italy and Iberia. Understanding modern patterns of diversity depends on understanding these historical population dynamics. Traditionally, European fallow deer (Dama dama dama) are thought to have been restricted to refugia in Anatolia and possibly Sicily and the Balkans. However, the distribution of this species was also greatly influenced by human-mediated translocations. We focus on fallow deer to better understand the relative influence of these natural and anthropogenic processes. We compared modern fallow deer putative populations across a broad geographic range using microsatellite and mitochondrial DNA loci. The results revealed highly insular populations, depauperate of genetic variation and significantly differentiated from each other. This is consistent with the expectations of drift acting on populations founded by small numbers of individuals, and reflects known founder populations in the north. However, there was also evidence for differentiation among (but not within) physically isolated regions in the south, including Iberia. In those regions we find evidence for a stronger influence from natural processes than may be expected for a species with such strong, known anthropogenic influence.

Influence of Holocene environmental change and anthropogenic impact on the diversity and distribution of roe deer.

Extant patterns of population structure and levels of diversity are a consequence of factors that vary in both space and time. Our objective in this study is to investigate a species that has responded to both natural and anthropogenic changes in ways that have shaped modern populations and provide insight into the key processes. The roe deer (Capreolus capreolus) is one of the two species of deer native to Britain. During the last glacial maximum (LGM), the British habitat was largely under ice and there was a land bridge to mainland Europe. As the Earth warmed during the early Holocene, the land bridge was lost. Subsequent hunting on the British mainland left the southern region extirpated of roe deer, whereas a refugial population remained in the north. Later reintroductions from Europe led to population expansion, especially in southern United Kingdom. Here, we combine data from ancient and modern DNA to track population dynamics and patterns of connectivity, and test hypotheses about the influence of natural and anthropogenic environmental change. We find that past expansion and divergence events coincided with a warming environment and the subsequent closure of the land bridge between Europe and the United Kingdom. We also find turnover in British roe deer haplotypes between the late-Holocene and modern day that have likely resulted from recent human disturbance activities such as habitat perturbation, overhunting and restocking.

Presence of Helicobacter pylori in drinking water is associated with clinical infection.

Helicobacter pylori was detected using molecular methods in untreated well water. The presence of H. pylori in the wells correlated with infection in consumers and with the presence of Escherichia coli, indicating fecal contamination. Consumption of untreated well water should be considered a risk factor for H. pylori infection.

Occurrence of Helicobacter pylori in surface water in the United States.

The primary mode of transmission of the human pathogen Helicobacter pylori is unresolved. This study examined the possibility that H. pylori is water-borne. Because methods for the direct culture of H. pylori from water samples remain elusive, a microscopic technique was used for detection of this organism. Actively respiring micro-organisms binding monoclonal anti-H. pylori antibody were found in the majority of surface and shallow groundwater samples tested (n = 62), indicating that H. pylori may be present in aquatic environments in the US and supporting a water-borne route of transmission for this organism. There was no significant correlation between the occurrence of either total coliforms or Escherichia coli in the water and the presence of H. pylori. Our results indicate that routine screening of water supplies for the presence of traditional indicator organisms may fail to protect the consumer from exposure to H. pylori.

Evaluation of endoscope sheaths as viral barriers.

OBJECTIVES: Evaluate ENT endoscope sheaths as barriers to virus passage. STUDY DESIGN: "Defective" sheaths covering an endoscope were challenged with virus to determine how many virus particles could be recovered from the endoscope. METHODS: Sheaths with small laser-drilled holes (2 to 30 microm) were challenged with high-titer virus suspensions (10(8) viruses/mL). The inside of the sheath and the endoscope were separately rinsed to recover any virus that penetrated through the hole in the sheath. In an attempt to assess the possible importance of holes in the sheaths, a sequential test was conducted with an initial virus challenge outside a defective sheath (30-micron hole in the sheath), after which the possibly contaminated endoscope was removed and inserted into a second defective sheath (with a 20-micron hole at the same location) to determine whether the contaminating virus would pass outward through the second sheath. RESULTS: Small volumes of virus-containing fluid penetrated through the hole, e.g., 500 virus particles passed through one of three 30-microm holes. A significant fraction of those virus particles was occasionally found on the endoscope after removal from the sheath. Similar results were obtained with sheaths that had small tears (34-84 microm in length, from punctures with fine wires). Although some virus penetration could occur during the initial challenge contaminating the endoscope, no virus was detected passing outward through the second sheath. CONCLUSIONS: Use of a sheath combined with intermediate level disinfection should provide a safe instrument for ENT endoscopy.

Thyroid cancer: a review.

Thyroid cancer is a rare and complex disease. The thyroid contains various cell types from which distinct diseases arise. These malignancies range from indolent to extremely aggressive. Diagnosis includes attention to risk factors, family history, and subjective reports. The most valuable tool for diagnosis is the fine-needle aspiration. Primary treatment is surgery with postoperative hormone therapy. Radiation and chemotherapy serve palliative and adjuvant roles in advanced, recurrent, or metastatic disease. Nurses make a significant contribution to patient understanding and successful treatment outcome.

Attachment as a factor in the protection of Enterobacter cloacae from chlorination.

Enterobacter cloacae attached to drinking water distribution particles was subjected to chlorination. Attachment resulted in the protection of these organisms from disinfection. This effect was found to be dependent upon both the level of chlorine in the system and attachment time. The results obtained in this study indicate that attached organisms may play an important role in coliform outbreaks.

Positive emotional states and enhancement of the immune system.

Salivary immunoglobulin A (IgA) concentration increased significantly after subjects viewed a humorous videotape and did not change significantly after they viewed a didactic videotape. Scores on a questionnaire measuring the perceived use of humor as a coping skill were positively related to initial IgA concentration and inversely related to changes in IgA concentration after subjects' viewing of the humorous videotape, which implies a ceiling effect. Enhancement of the immune system may be one link between anecdotal claims of relationships between an individual's being in a positive emotional state and healing.

Effects of selected assay parameters on measurement of lignocellulose mineralization with a radiolabeled substrate.

Varying the amount of labeled substrate or the amount of leaf material resulted in significant nonlinear changes in lignocellulose mineralization, as measured with natural [C]lignin-labeled lignocellulose. The use of periodic rather than continuous aeration was found not to have significant effects on measured mineralization.

Determination of the Number of Respiring Thiobacillus ferrooxidans Cells in Water Samples by Using Combined Fluorescent Antibody-2-(p-Iodophenyl)-3-(p-Nitrophenyl)-5-Phenyltetrazolium Chloride Staining.

Fluorescent antibody staining was combined with 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride reduction in a procedure termed FAINT to allow for the direct microscopic determination of specific actively respiring populations of bacteria in a variety of aquatic habitats. The FAINT procedure is simple, precise, and appropriate for use in a wide variety of autecological studies. The distribution of Thiobacillus ferrooxidans was examined by FAINT enumerations in both acidic and nonacidic sites. Comparisons among the FAINT technique and fluorescent antibody staining alone or most-probable-number determinations in 9K broth showed that the use of most-probable-number determinations resulted in an underestimation of the number of viable cells by one to three orders of magnitude, whereas fluorescent antibody counts resulted in an overestimation of the number of viable T. ferrooxidans. The amount of difference was not consistent but varied, depending on the sample site.

Interactions between the diatom Thallasiosira pseudonanna and an associated pseudomonad in a mariculture system.

The marine diatom Thallasiosira pseudonanna (3H) and several bacteria associated with it were isolated from batch cultures at the University of Delaware mariculture facility. The interaction between the algae and each of the bacteria was investigated. One of the isolates, T827/2B (Pseudomonas sp.), was incapable of surviving in f/2 culture medium unless the algae were present. When the algae and T827/2B were grown together in the f/2 medium, the bacterial growth was stimulated and the algal growth was inhibited. Bacterial filtrate had a similar effect on the algae, indicating that the bacterial effect is an indirect one most likely resulting from the excretion of a harmful compound into the medium. Preliminary characterization of the material excreted by the bacteria indicates that it s proteinaceous in nature. The interactions observed does not fit into any single category of interactions but can be explained as a combination of competition and indirect parasitism.