Novel repellents for the blood-sucking insects Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease

Background: Studying the behavioral response of blood-sucking disease-vector insects to potentially repellent volatile compounds could shed light on the development of new control strategies. Volatiles released by human facial skin microbiota play different roles in the host-seeking behavior of triatomines. We assessed the repellency effect of such compounds of bacterial origin on Triatoma infestans and Rhodnius prolixus, two important vectors of Chagas disease in Latin America. Methods: Using an exposure device, insects were presented to human odor alone (control) and in the presence of three individual test compounds (2-mercaptoethanol, dimethyl sulfide and 2-phenylethanol, the latter only tested in R. prolixus) and the gold-standard repellent NN-diethyl-3-methylbenzamide (DEET). We quantified the time the insects spent in the proximity of the host and determined if any of the compounds evaluated affected the behavior of the insects. Results: We found volatiles that significantly reduced the time spent in the proximity of the host. These were 2-phenylethanol and 2-mercaptoethanol for R. prolixus, and dimethyl sulfide and 2-mercaptoethanol for T. infestans. Such an effect was also observed in both species when DEET was presented, although only at the higher doses tested. Conclusions: The new repellents modulated the behavior of two Chagas disease vectors belonging to two different triatomine tribes, and this was achieved using a dose up to three orders of magnitude lower than that needed to evoke the same effect with DEET. Future efforts in understanding the mechanism of action of repellent compounds such as 2-mercaptoethanol, as well as an assessment of their temporal and spatial repellent properties, could lead to the development of novel control strategies for these insect vectors, refractory to DEET.Fil: Ramírez, Melanie. Universidad de los Andes; ColombiaFil: Ortiz, Mario I.. Universidad de los Andes; ColombiaFil: Guerenstein, Pablo Gustavo. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Molina, Jorge Luis. Universidad de los Andes; Colombi

Inconsistency of a dissipative contribution to the mass flux in hydrodynamics

The possibility of dissipative contributions to the mass flux is considered in detail. A general, thermodynamically consistent framework is developed to obtain such terms, the compatibility of which with general principles is then checked--including Galilean invariance, the possibility of steady rigid rotation and uniform center-of-mass motion, the existence of a locally conserved angular momentum, and material objectivity. All previously discussed scenarios of dissipative mass fluxes are found to be ruled out by some combinations of these principles, but not a new one that includes a smoothed velocity field v-bar. However, this field v-bar is nonlocal and leads to unacceptable consequences in specific situations. Hence we can state with confidence that a dissipative contribution to the mass flux is not possible.Comment: 18 pages; submitted to Phys. Rev.

Effect of Diclofenac with B Vitamins on the Treatment of Acute Pain Originated by Lower-Limb Fracture and Surgery

The aim of this study was to compare the efficacy of diclofenac, for the treatment of acute pain originated by lower-limb fracture and surgery, with that of diclofenac plus B vitamins. This was a single-center, prospective, randomized, and double-blinded clinical trial. Patients with lower-limb closed fractures rated their pain on a 10 cm visual analog scale (VAS). Patients were then randomized to receive diclofenac or diclofenac plus B vitamins (thiamine, pyridoxine, and cyanocobalamin) intramuscularly twice daily. Patient evaluations of pain intensity were recorded throughout two periods: twenty-four hours presurgery and twenty-four hours postsurgical. One hundred twenty-two patients completed the study. The subjects' assessments of limb pain on the VAS showed a significant reduction from baseline values regardless of the treatment group. Diclofenac plus B vitamins combination was more effective to reduce the pain than diclofenac alone. The results showed that the addition of B vitamins to diclofenac increased its analgesic effect. The novelty of this paper consists in that diclofenac and diclofenac plus B vitamins were useful for treatment of acute pain originated by lower-limb fracture and surgery

‘The forgotten sex’: gender disparities in kidney disease

No abstract available

Implementation of UV rotational Raman channel to improve aerosol retrievals from multiwavelength lidar

Vibrational Raman effect is widely used in atmospheric lidar systems, but rotational Raman present several advantages. We have implemented a new setup in the ultraviolet branch of an existing multiwavelength lidar system to collect signal from rotational Raman lines of Oxygen and Nitrogen. We showed that, with an appropriate filter wavelength selection, the systematic error introduced in the particle optical properties due to temperature dependence was less than 4%. With this new setup, we have been able to retrieve aerosol extinction and backscatter coefficients profiles at 355 nm with 1-h time resolution during daytime and up to 1-min time resolution during nighttime.Grupo de Física de la Atmósfera (RNM119

Corn price volatility and producer income protection

Objective: To estimate the indicator of the risk of the future price of yellow corn #2 of the Chicago Futures Exchange in the United States to the spot price of white corn in the main white corn producing regions of Mexico through the financial volatility indicator. Methodology: The research used the returns of the monthly time series for the period January 1998 to December 2020 corresponding to the spot price of white corn for five producer-consumer regions of Mexico and the futures price of yellow corn #2 listed on the Chicago Stock Exchange. To quantify volatility, the generalized autoregressive conditional heteroskedasticity model of order (1,1) was estimated. Results: The volatility indicator for yellow corn turned out to be 0.9870 for the futures price of quality 2 yellow corn. In the case of the spot price of white corn in Mexico, the volatility was 0.0.7977 for the national price; 0.3385 for the central region; 0.3206 for the western region and 0.0078 for the southeastern region, respectively. Implications: The high volatility of yellow corn #, close to unity, shows that the international market for this commodity is riskier than the national market or the regional markets in Mexico. Conclusions: The national white corn market showed to be more risky than the western, central and southeastern regional markets, showing a higher volatility indicator.O Objective: To estimate the risk indicator of the future price of yellow corn #2 at the Chicago Futures Exchange (USA) regarding the spot price of white corn in the main producing regions in Mexico through the financial volatility indicator. Methodology: The research used the returns of the monthly time series corresponding to the spot price of white corn from January 1998 to December 2020, considering five producer-consumer regions of Mexico and the future price of yellow corn #2 as listed on the Chicago Stock Exchange. To quantify volatility, the generalized autoregressive conditional heteroskedasticity model of order (1,1) was estimated. Results: The yellow corn #2 volatility indicator was 0.9870 (future price). In the case of the spot price of white corn in Mexico, the volatility was 0.7977 for the national price, 0.3385 for the central region, 0.3206 for the western region, and 0.0078 for the southeast region. Implications: The high volatility of yellow corn #2 (close to unity) shows that the international market for this commodity is riskier than the national market or regional markets in Mexico. Conclusions: The national white corn market proved to be riskier than the west, center, and southeast regional markets, which have a higher volatility indicator

Contribution of genetic and epigenetic mechanisms to Wnt pathway activity in prevalent skeletal disorders

Producción CientíficaWe reported previously that the expression of Wnt-related genes is lower in osteoporotic hip fractures than in 26 osteoarthritis. We aimed to confirm those results by analyzing β-catenin levels and explored potential genetic 27 and epigenetic mechanisms involved. 28 β-Catenin gene expression and nuclear levelswere analyzed by real time PCR and confocal immunofluorescence. 29 Increased nuclear β-catenin was found in osteoblasts isolated from patients with osteoarthritis (99 ± 4 30 units vs. 76 ± 12, p = 0.01, n = 10), without differences in gene transcription, which is consistent with 31 a post-translational down-regulation of β-catenin and decreased Wnt pathway activity. 32 Twenty four single nucleotide polymorphisms (SNPs) of genes showing differential expression between fractures 33 and osteoarthritis (WNT4, WNT10A, WNT16 and SFRP1) were analyzed in DNA isolated from blood of 853 pa- 34 tients. The genotypic frequencies were similar in both groups of patients, with no significant differences. 35 Methylation ofWnt pathway genes was analyzed in bone tissue samples (15 with fractures and 15 with osteo- 36 arthritis) by interrogating a CpG-based methylation array. Six genes showed significant methylation differences 37 between both groups of patients: FZD10, TBL1X, CSNK1E, WNT8A, CSNK1A1L and SFRP4. The DNA demethylating 38 agent 5-deoxycytidine up-regulated 8 genes, including FZD10, in an osteoblast-like cell line, whereas it down- 39 regulated other 16 genes. 40 In conclusion,Wnt activity is reduced in patientswith hip fractures, in comparisonwith thosewith osteoarthritis. 41 It does not appear to be related to differences in the allele frequencies of the Wnt genes studied. On the other 42 hand, methylation differences between both groups could contribute to explain the differences inWnt activit

Effect of maize processing on amylose-lipid complex in pozole, a traditional Mexican dish

One of the most traditional foods in Mexico is pozole (a soup of maize grains with pork). Maize starch interacts with fatty acids during its preparation, generating amylose-lipid complexes. This study aimed to determine the effect of lard concentration on the formation of amylose-lipid complexes and their effect on the physicochemical properties of the starch after pozole preparation. Three maize varieties were nixtamalized and cooked, using 0, 6, 8, and 10 % lard. Grain physical parameters, viscosity, resistant starch, and detailed characterization of starch granules were analyzed. X-ray diffraction patterns showed structural damage in the crystalline starch structure. Two of the maize varieties showed an amylose-lipid endotherm with the addition of lard. The viscosity profile was affected by grain hardness and heat treatment, whereas lard addition decreased the viscosity of samples. The addition of higher percentages of lard (8 and 10%) favors the formation of amylose-lipid complexes, as shown in thermal properties and resistant starch