Illustration of the modified arena.

<p>(<b>A</b>) A Dudley tube painted black from inside was flanked by 2 cotton rolls secured in place by syringe needles that delivered CO₂. Samples of defibrinated sheep blood mixed with solvent only or spiked with DEET were loaded on these cotton rolls, which were subsequently covered with Parafilm. (<b>B</b>) An aerial view of the arena. Mosquitoes were placed on a mosquito cage accessible from the top and having a camera (not shown) attached to the left. The Dudley tube was connected to a water bath (not shown) and the syringe needles to a CO₂ tank (not shown).</p

DEET as a feeding deterrent

<div><p>The insect repellent <i>N</i>,<i>N</i>-diethyl-3-methylbenzamide (DEET), is a multimodal compound that acts as a spatial repellent as well as an irritant (contact repellent), thus being perceived by the insect’s olfactory and gustatory systems as an odorant and a tastant, respectively. Soon after DEET was developed, almost 6 decades ago, it was reported that it reduced mosquito feeding on blood mixed with this repellent. It is now known that the mosquito proboscis senses contact repellents with the tips (labella) of the labium, which remain in direct contact with the outer layers of the skin, while the stylets, including the feeding deterrent sensor (labrum), penetrate the skin. We designed a behavioral assay that allowed us to measure feeding deterrence without complications from contact or spatial repellency. Using the southern house mosquito, <i>Culex quinquefasciatus</i>, we demonstrate here that when DEET was mixed with blood and covered by Parafilm® layers, the mean number of landings and duration of contacts with surfaces covering blood mixed with DEET or blood plus solvent (dimethyl sulfoxide) did not differ significantly thus implying that DEET did not leak to the outer surface. The feeding times, however, were significantly different. When blood was mixed either with 0.1 or 1% DEET, female southern house mosquitoes spent significantly (P<0.0001) less time feeding than the time spent feeding on blood mixed only with the solvent. By contrast, significant differences in the mean times of feeding on blood containing 1% picaridin and blood plus solvent were significant at 5%, but not at 1% level. Like DEET, the contact repellent and insecticide, permethrin, caused a significant (P<0.0001) reduction in feeding time. We, therefore, concluded, that in this context, DEET, permethrin, and, to a lesser extent, picaridin, act as feeding deterrents.</p></div

Comparative feeding times on blood mixed with solvent or test repellents.

<p>(<b>A</b>) 0.1% DEET, (<b>B)</b> 1% DEET, (<b>C</b>) 1% picaridin, and (<b>D</b>) 1% permethrin.</p

Methyl dihydrojasmonate and lilial are the constituents with an "off-label" insect repellence in perfumes - Fig 3

<p><b>Repellence activity elicited by mixtures of methyl dihydrojasmonate and lilial at (A) 1% and (B) 5% compared with responses to DEET at the same concentration.</b> Data were normalized and expressed as mean ± SEM. Asterisks denote significant differences of transformed data (Student <i>t</i> test, P < 0.05). The number of replicates were (A) mixture, n = 13; DEET, n = 12; (B) mixture and DEET, n = 6.</p

Comparison of individuals with CAN in low- and high-score groups.

<p>Note: BMI- Body mass index, SBP- systolic blood pressure, DBP- diastolic blood pressure, FPG- fasting plasma glucose, PBG- plasma blood glucose, TC- serum total cholesterol, TG- triglyceride, UA- uric acid, HDL- high-density lipoprotein cholesterol, LDL- low density lipoprotein cholesterol, HR-heart rate, MS- metabolic syndrome, HT- Hypertension, DM- Diabetes.</p

Artificial neural network model showing input variables (nodes), hidden nodes, and connection weights with output node for data on CA dysfunction.

<p>The ANN model including 14 input nodes, 18 hidden nodes and 1 output node. Data from a total of 2077 patients had been used to ANN analysis. BMI- Body mass index, WC-waist circumference, SBP- systolic blood pressure, DBP- diastolic blood pressure, FPG- fasting plasma glucose, PBG- plasma blood glucose, IR-insulin resistance, TG- triglyceride, UA- uric acid, HR-heart rate, PH- Hypertension, DM- Diabetes, PHD- Hypertension duration, DMD- Diabetes duration.</p

Univariate analysis of risk factors for CAN (ranking by coefficient).

<p>Note: HR-heart rate, FPG- fasting plasma glucose, PBG- plasma blood glucose, TG- triglyceride, BMI-body mass index, HT- Hypertension, DM- Diabetes, MS-metabolic syndrome.</p

CAN risk score based on the simple model in the exploratory set.

<p>Note:</p><p>*For each significant variable in the multiple logistic regression analysis, a risk score was calculated from the regression coefficients (<i>β</i>) dividing by a common factor (0.236) and rounding to the nearest integer.</p

Improved Variable Selection Algorithm Using a LASSO-Type Penalty, with an Application to Assessing Hepatitis B Infection Relevant Factors in Community Residents

<div><p>Objectives</p><p>In epidemiological studies, it is important to identify independent associations between collective exposures and a health outcome. The current stepwise selection technique ignores stochastic errors and suffers from a lack of stability. The alternative LASSO-penalized regression model can be applied to detect significant predictors from a pool of candidate variables. However, this technique is prone to false positives and tends to create excessive biases. It remains challenging to develop robust variable selection methods and enhance predictability.</p><p>Material and methods</p><p>Two improved algorithms denoted the two-stage hybrid and bootstrap ranking procedures, both using a LASSO-type penalty, were developed for epidemiological association analysis. The performance of the proposed procedures and other methods including conventional LASSO, Bolasso, stepwise and stability selection models were evaluated using intensive simulation. In addition, methods were compared by using an empirical analysis based on large-scale survey data of hepatitis B infection-relevant factors among Guangdong residents.</p><p>Results</p><p>The proposed procedures produced comparable or less biased selection results when compared to conventional variable selection models. In total, the two newly proposed procedures were stable with respect to various scenarios of simulation, demonstrating a higher power and a lower false positive rate during variable selection than the compared methods. In empirical analysis, the proposed procedures yielding a sparse set of hepatitis B infection-relevant factors gave the best predictive performance and showed that the procedures were able to select a more stringent set of factors. The individual history of hepatitis B vaccination, family and individual history of hepatitis B infection were associated with hepatitis B infection in the studied residents according to the proposed procedures.</p><p>Conclusions</p><p>The newly proposed procedures improve the identification of significant variables and enable us to derive a new insight into epidemiological association analysis.</p></div

Behavioral responses of blood-seeking female <i>Culex</i> mosquitoes to the major constituents of Bombshell in a surface landing and feeding assay.

<p>(A) Methyl dihydrojasmonate (MDJ), (B) lilial, (C) isopropyl myristate (IM), (D) galaxolide and lyral–the latter was found in Ivanka Trump eau de parfum. All compounds were tested at 1% dose, and DEET at the same dose was used as a positive control. Data were normalized and expressed as mean ± SEM. Asterisks and “ns” indicate significant (Student <i>t</i> test, P < 0.05) and not significant differences, respectively. The number of replicates were (A), DEET, n = 12; MDJ, n = 11; (B) DEET, n = 8; lilial, n = 10; (C), DEET and IM, n = 4; (D) galaxolide and lyral (n = 6).</p