Adjunctive subantimicrobial dose doxycycline in the management of institutionalised geriatric patients with chronic periodontitis

Objective: To assess the efficacy of subantimicrobial dose doxycycline (SDD; 20 mg doxycycline twice daily) as an adjunct to scaling and root planing (SRP) in the treatment of moderate‐severe chronic periodontitis (CP) in institutionalised elderly patients aged 65 years or older. Background: Previous studies have shown that SDD is of clinical benefit in the treatment of CP. However, the benefits of SDD in geriatric populations (65+ years) have not been determined. Material and methods: A 9‐month, double‐blind, randomised, placebo‐controlled pilot study was conducted. 24 institutionalised geriatric patients (65 years or older) with evidence of CP manifested by baseline clinical attachment levels (CAL) 5–9 mm, probing depths (PD) 4–9 mm and bleeding on probing (BOP) were recruited. At baseline, patients were treated by a standardised episode of SRP, and randomised to receive either adjunctive SDD or placebo. Full mouth PD and CAL were measured using the manual UNC‐15 periodontal probe at 3, 6, and 9 months post‐baseline to assess the response to treatment. Periodontal sites were stratified by baseline PD value: sites with PD 4–5 mm were considered moderately diseased and sites with PD ≥6 mm severely diseased. Results: The SRP + placebo resulted in PD reductions similar to those reported previously in the literature. At all time‐points and in both moderate and deep sites, SRP + SDD resulted in significantly greater PD reductions relative to baseline than SRP + placebo. At month 9, in moderate sites, mean PD reductions of 1.57 ± 0.11 mm were reported in the adjunctive SDD group, compared with 0.63 ± 0.11 mm in the adjunctive placebo group (p < 0.001). In deep sites at month 9, mean PD reductions of 3.22 ± 0.29 mm were reported in the adjunctive SDD group, compared with 0.98 ± 0.31 mm in the adjunctive placebo group (p < 0.05). Similar improvements were observed for CAL in the SDD group compared with the placebo group. Significantly lower BOP scores were also recorded at month 9 in the SDD group (7.5%) compared with the placebo group (71.2%) (p < 0.01). Conclusion: SDD used as an adjunct to SRP provides significant benefit for elderly patients with CP compared with SRP alone.     

Blind Count Surveys of White-Tailed Deer and Population Estimates Using Bowden's Estimators

Abstract: Conducting surveys from blinds when supplemental feed (bait) has been provided has not been evaluated for estimating parameters of ungulate populations. We conducted blind count surveys of white-tailed deer (Odocoileus virginianus) in a 214-ha enclosure in central Texas, USA, in 2007 and 2008 to address 2 main objectives: 1) to evaluate a blind count survey protocol developed for use on small parcels of land, and 2) to use data collected from blind count surveys to conduct simulations to evaluate the reliability of abundance and sex ratio estimates obtained from Bowden's estimator. In each year population abundance (2007: 60; 2008: 48) and sex ratio (M:F, 2007: 0.58; 2008: 0.71) were known as were sighting frequencies of every animal. The enclosure had 5 blinds and we baited each blind with corn. We encountered many deer during surveys because there were only 2 deer in 2007 and 1 deer in 2008 that we did not view from blinds ≥1 time. To evaluate bias and precision of abundance and sex ratio estimates we conducted 10,000 bootstrap simulations. We evaluated both parameters in relation to the percentage of each population marked, number of surveys conducted from blinds, and whether surveys were conducted in the morning, evening, or both morning and evening. Also, we evaluated abundance in relation to whether we identified animals with unique marks to individual, and we evaluated sex ratio in relation to intersexual distribution of marks. Abundance estimates were less biased and more precise when we uniquely identified all marked animals and 40–70% of the population was marked. Sex ratio estimates were less biased when 40–70% of the population was marked and surveys were conducted in the morning and evening. Sex ratio estimates, however, were less precise than abundance estimates. Unbiased estimates of white-tailed deer population parameters can be obtained from blind count surveys conducted on small parcels of enclosed land and when animals are baited.     

A genetic tool kit for cellular and behavioral analyses of insect sugar receptors

Arthropods employ a large family of up to 100 putative taste or gustatory receptors (Grs) for the recognition of a wide range of non-volatile chemicals. In Drosophila melanogaster, a small subfamily of 8 Gr genes is thought to mediate the detection of sugars, the fly's major nutritional source. However, the specific roles for most sugar Gr genes are not known. Here, we report the generation of a series of mutant sugar Gr knock-in alleles and several composite sugar Gr mutant strains, including a sugar blind strain, which will facilitate the characterization of this gene family. Using Ca²⁺ imaging experiments, we show that most gustatory receptor neurons (GRNs) of sugar blind flies (lacking all 8 sugar Gr genes) fail to respond to any sugar tested. Moreover, expression of single sugar Gr genes in most sweet GRNs of sugar-blind flies does not restore sugar responses. However, when pair-wise combinations of sugar Gr genes are introduced to sweet GRNs, responses to select sugars are restored. We also examined the cellular phenotype of flies homozygous mutant for Gr64a, a Gr gene previously reported to be a major contributor for the detection of many sugars. In contrast to these claims, we find that sweet GRNs of Gr64a homozygous mutant flies show normal responses to most sugars, and only modestly reduced responses to maltose and maltotriose. Thus, the precisely engineered genetic mutations of single Gr genes and construction of a sugar-blind strain provide powerful analytical tools for examining the roles of Drosophila and other insect sugar Gr genes in sweet taste.     

一种基于可穿戴器件触觉感知信息的盲人虚拟视觉导航系统

目的 全球视力受损或失明人数已超2亿，长期以来各类人工视觉系统被广泛研究。人工视觉系统的研发主要有两种技术路径，第一种是各类植入式人工视觉装置，第二种是各类非植入式、可穿戴装置。本文展示了一种非植入式、基于可穿戴头部触觉激发装置的系统原型，能够帮助盲人和视觉障碍者完成行走等复杂任务。方法 该系统采集受试者周边环境图像信息并无线传输到后台，操作人员分析处理图像信息后，将指令以触觉编码形式无线传输到头套等可穿戴装置，由驱动电路激发多点位头部触觉，从而为受试者提供准确的行动指令。系统并辅助以语音信息，让其了解更多道路状况和环境信息。结果 用原型系统对5名（2男3女）在读大学生健康志愿者和1名年轻盲症患者（男）进行实验。结果表明，原型系统充分利用了头部对前后左右的天然区分能力和对触觉的快速反应，具备直行、左右调整、转弯等明确指令功能。受试者对指令的响应时间约0.5 s，直线行走约7 m距离的偏差量标准差平均值相比未佩戴装置的情况下降低到（16±10）cm。结论 该系统可隐蔽、准确地提供环境图像信息，有效帮助视觉障碍人士完成行走、避让障碍物、上台阶、进入咖啡厅等公共场所、桌上取物等日常活动，达到了预期目标。今后对原型系统作进一步完善，特别是小型化、智能芯片化，把触觉装置制成颈环、腰带、手环、脚环等，将能够广泛应用于盲人出行辅助、夜间野外旅行、深海潜水等多种工作场景。