Suicide and economic uncertainty: New findings in a global setting.

This study extends the previous literature on the association between country-level economic uncertainty and suicide rate to 141 countries by introducing the World Uncertainty Index. We first examine the role of economic uncertainty on the suicide rates in a global setting for the period 2000-2019 and then analyze if the association varied across different income groups. Our primary findings suggest that a rise in economic uncertainty is related to an increased suicide rate. According to the estimates based on various income levels, higher economic uncertainty is associated with increased suicide risk in high-income countries. For middle- and low-income countries, we find no such impact. Overall, we conclude that contemporaneous and lagged economic uncertainty is a concern for the increased risk of suicide, especially in high-income countries. The results highlight the need for proactive suicide-prevention strategies in uncertain times.

Suicide as globalisation's Black Swan: global evidence.

OBJECTIVES: This empirical study investigated the relationship between globalisation and suicide rates. We examined whether there is a beneficial or harmful relationship between economic, political and social globalisation and the suicide rate. We also estimated whether this relationship differs in high-, middle- and low-income countries. STUDY DESIGN: Using panel data from 190 countries over the period 1990-2019, we examined the relationship between globalisation and suicide. METHOD: We compared the estimated effect of globalisation on suicide rates using robust fixed-effects models. Our results were robust to dynamic models and models with country-specific time trends. RESULTS: The effect of the KOF Globalisation Index on suicide was initially positive, leading to an increase in the suicide rate before decreasing. Concerning the effects of economic, political, and social dimensions of globalisation, we found a similar inverted U-shaped relationship. Unlike the middle-income and high-income countries, we found a U-shaped relationship for the case of low-income countries, indicating that suicide decreased with globalisation and then increased as globalisation continues to increase. Moreover, the effect of political globalisation disappeared in low-income countries. CONCLUSION: Policy-makers in high- and middle-income countries, below the turning points, and low-income countries, above the turning points, must protect vulnerable groups from globalisation's disruptive forces, which can increase social inequality. Consideration of local and global factors of suicide will potentially stimulate the development of measures that might reduce the suicide rate.

High temperatures are associated with substantial reductions in breeding success and offspring quality in an arid-zone bird.

During hot weather, terrestrial animals often seek shaded thermal refugia. However, this can result in missed foraging opportunities, loss of body condition and impaired parental care. We investigated whether such costs could compromise breeding success in a widespread southern African bird: the Southern Yellow-Billed Hornbill Tockus leucomelas. We predicted that hornbills might be especially vulnerable to temperature-dependant reductions in parents' foraging capacity due to extreme asymmetry in sex-specific roles during breeding: females are confined within the nest cavity for most of the nesting period and the burden of provisioning falls solely on the male during this time. We followed 50 hornbill nesting attempts in the Kalahari Desert between 2012 and 2015, collecting data on provisioning rates, adult and nestling body mass, fledging success and size of fledglings. Mean daily maximum air temperatures (Tmax) during nesting attempts ranged from 33.2 to 39.1 °C. The likelihood of successful fledging fell below 50% at mean Tmax > 35.1 °C; a threshold now regularly exceeded at our study site due to recent climate warming. Additionally, offspring fledging following the hottest nesting attempts were > 50% lighter than those fledging following the coolest. Sublethal costs of keeping cool including loss of body condition, production of poor-quality offspring and breeding failure are likely to become issues of serious conservation concern as climate change progresses; even for currently widespread species. Missed-opportunity costs associated with behavioral thermoregulation and direct sublethal costs of temperature exposure should not be overlooked as a potential threat to populations, especially in environments that are already hot.

Influence of defect locations and nitrogen doping configurations on the mechanical properties of armchair graphene nanoribbons.

The effect of defect locations on the mechanical properties of armchair graphene nanoribbons (AGNRs) and the various configurations of nitrogen (N) doping on the mechanical properties of AGNRs were examined using molecular dynamics (MD) simulations. The variation of the Young's modulus (YM) and the ultimate tensile strength (UTS) of pyridinic-N, graphitic-N, and pyrrolic-N by increasing the concentration of N doping was investigated. The results of MD simulations show that the defect location has a significant effect on the UTS and failure strain (FS) of AGNRs in both vertical and horizontal directions. In the horizontal direction, variations of the UTS and FS are lower than in the vertical direction. On the other hand, the variations of the YM is almost similar in vertical and horizontal directions. The results of this work indicate that the UTS and FS of AGNRs are more sensitive than the YM of AGNRs for different defect directions. Pyridinic-N improves the mechanical properties of the defective AGNR and performs better YM and UTS values than the graphitic-N. Substitution N atoms, which are located at the defective sites and/or at the edges of AGNRs, are mechanically more favorable. Pyrrolic-N configuration has the lowest mechanical properties among the other configurations. Furthermore, pyrrolic-N with Stone-Wales-1 (SW-1) type of defect has higher mechanical properties than pyrrolic-N with Stone-Wales-2 (SW-2) type of defect.

Effects of the nitrogen doping configuration and site on the thermal conductivity of defective armchair graphene nanoribbons.

The influence of the nitrogen (N) doping configuration on the thermal conductivity (TC) of armchair graphene nanoribbons (AGNRs) of size 15.7 nm × 7.26 nm was investigated using classical molecular dynamics (MD) simulations with the optimized Tersoff potential at room temperature. The effect of changing the N-doping site in defects on the TC of AGNRs was also investigated in detail. The variations with N concentration of the TCs of AGNRs presenting graphitic N (quarternary N), pyridinic N, and pyrrolic N doping configurations were studied. Results of MD simulations showed that, among these three doping configurations, pyridinic N was associated with the highest TC, and pyrrolic N with the lowest TC. The highest TC values were obtained when the N dopant atoms were located at the edges and at defects in the AGNR. The presence of both pyrrolic N and Stone-Wales type 1 (SW-1) defects led to a higher TC than the presence of both pyrrolic N and SW-2 defects. Phonon-defect scattering was found to be influenced by changes in C-C bond orientation. SW-1 defects were found to exert a greater influence on the TC than graphitic N doping. Furthermore, the influence on the TC of the N-doping site location in SW-1 defects was examined. Doping the central sites of SW-1 defects was found to yield higher TC values than doping the edge sites of defects. Graphitic-N doping of the more central sites in a SW-1 defect led to a higher TC than the random graphitic-N doping of sites in a SW-1 defect.

Hemolink-induced effects on intestinal motor function and attenuation of these effects by selected agents.

Hemolink, an oxidized, ring-opened raffinose-crosslinked hemoglobin-based oxygen carrier produced by Hemosol Inc., stimulates esophageal peristalsis, possibly by interference with neural NO-mediated effects. The effects of Hemolink on jejunal tone and contractions, arterial pressure and heart rate were measured in anesthetized rats, and the effect of selected agents in attenuating or reversing these effects was studied. Infusion of L-NAME was used to validate the study model; it caused an immediate increase in tone and initiated phasic contractions indicating that the model was responsive to NO-mediated effects. Hemolink administration caused effects on intestinal motor function similar to those caused by L-NAME, including increases in basal tone and contraction amplitude. Rat whole blood caused none of these changes. The Hemolink-induced effects were less immediate in some animals compared to those observed after L-NAME. As well there was greater inter-animal variability on the effects. Hemolink administration also caused a mild increase in arterial blood pressure and a reciprocal decrease in heart rate in some animals. Co-administration of morphine, a common analgesic that has been reported to influence the motility of the GI tract; L-arginine, a substrate for NO synthesis; and glycopyrrolate, an anti-cholinergic agent, did not significantly modulate the Hemolink effects, whereas nitroglycerin, an NO donor; and nifedipine, a slow calcium-channel blocker, attenuated or reversed these effects.

From the Journals.

Venous leg ulcers and effects of aspirin therapy The design of compression hosiery A topical copper complex in treating leg ulcers Therapeutic potential of LS-2616 Biofilm dressings and bacterial permeability.

Pharmacokinetic studies in the rat on a o-raffinose polymerized human hemoglobin.

We have studied the plasma half-life (T 1/2), oxygen-binding affinity (P50), organ distribution, and excretion of the individual molecular weight (MW) components of human hemoglobin polymerized with periodate-oxidized, ring-opened raffinose (oR poly-Hb), following transfusion in the rat. The model was an isovolemic 50% exchange transfusion in the conscious, chronically catheterized rat. Total plasma Hb levels yielded a (T 1/2) of 10 to 11 hr for oR poly-Hb. The T 1/2 values of individual MW components of the poly-Hb as determined by size-exclusion HPLC were approximately: 4 hr for the monomeric fraction (Hb)1, 9 hr for the dimer (Hb)2, and 15 hr for the fraction representing trimers to nanomers (Hb)3-9. The P50 values of plasma samples containing oR poly-Hb (collected from 0-24 hr after exchange) remained unchanged at 28 +/- 3 mmHg. oR stabilized and polymerized Hb were not excreted via the kidneys. Hepatic and renal distribution as well as plasma and renal clearance were determined by liquid scintillation counting using individual tritium [3H] labelled MW components purified from [3H]-oR poly-Hb: (Hb)1/2, (Hb)1, (Hb)2, (Hb)3&4, and (Hb) greater than 9. In kidney, uptake (determined by the relative concentration of radioactivity) decreased with increasing MW of the labelled component. Conversely, in liver, uptake increased with increasing MW. Plasma and renal clearance results were consistent with those obtained by HPLC analysis. Hematocrit levels returned from a 20% post-transfusion level to normal pre-transfusion levels (44%) within 10 days after the exchange.

[The detection of opisthorchiasis foci in Byelorussia]. / Vyiavlenie ochagov opistorkhoza v Belorussii.

Local foci of opisthorchiasis have been established on the territory of 3 Belorussian districts (Brest, Gomel and Grodno provinces). Human beings, cats, fish and the first intermediate host mollusk invaded with Opisthorchis have been found.

Simple serological tests for detecting classical heat labile enterotoxin (LT-I) of Escherichia coli.

Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) remains a problem in Southeast Asia. At present, no routine laboratories as yet are available for ETEC detection. In this study, attempts were made to produce reagents for use in simple serological tests for detecting LT. The serological methods were the Biken, the staphylococcal coagglutination and the reverse passive hemagglutination tests. For the Biken test, medium was prepared locally by mixing constituents as described previously by Honda et al., (1981). Anti-CT-B subunit was prepared by immunizing a rabbit with commercial CT-B subunits (Sigma). Other chemical reagents e.g. colistin, lincomycin etc. were obtained from the local supplies. Using the locally made reagents to detect LT from 100 WHO reference strains of E. coli by the Biken test, it was found that the test had 100%, 92%, 96%, 100% and 92.5% of specificity, sensitivity, accuracy, positive predictive value and negative predictive value, respectively. Protein A rich Staphylococcus aureus from the stock culture of the Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University were grown in suitable medium i.e. blood agar containing lincomycin (BA-Lin). Suitable amount of the rabbit anti CT-B subunit (0.1 ml) was used to sensitize each ml of the formalinized, heat-fixed bacteria. The sensitized bacteria were used for detecting LT in the lysates of the 100 E. coli reference strains. The lysates were prepared by growing the E. coli strains on BA-Lin medium for 8 hours, then a loopful of each strain was inoculated into colistin solution (20,000 unit/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Quality control of hemoglobin-based blood substitutes.

Preparation and use of hemoglobin-based blood substitutes, from stroma-free hemoglobin (SFH or Hb) and its DPG analogue-modified derivatives (PLP-Hb, ATP-Hb etc.) without thorough characterization and quality control in animal or human testing have produced, and may continue to produce, artifacts in the finished product. Thus the development of such a natural substitute for the volume expansion and oxygen delivery functions of the blood will be impeded. A case is made for the use of affinity purified hemoglobin and modified hemoglobin as standard starting materials for the preparation of Hb-based blood substitute(s) in general, and in particular poly PLP-Hb. Development of a commercial scale blood-substitute is only possible after the safety and toxicity issues of substitutes have been resolved by applying rigorous quality control.

Hemoglobin-based blood substitutes: characterization of five pyridoxal 5'-phosphate derivatives of hemoglobin.

Six fractions (I-VI) of pyridoxal 5'-phosphate (PLP) hemoglobin (Hb), prepared by the method of De Venuto and Zegna [J. Surg. Res., 34 (1983) 205] have been isolated and purified by anion-exchange high-performance liquid chromatography (HPLC). Total phosphate analyses indicate that I is HbA, II and III are double-labelled, IV and V are tetra-labelled and VI contains 6 mol of phosphorus per mol of hemoglobin. The purified components have been resolved into their alpha and beta chains by preparative reversed-phase HPLC using a macroporous C4 support. Phosphate analyses indicate that the beta chains of II, III and IV each contain one phosphate per chain while the beta chains of V and VI each contain two phosphates. The alpha chains of IV and VI were found to be monophosphate-labelled. Reversed phase HPLC analysis of the tryptic peptides of the beta chains indicates that the label is bound exclusively to the 1-valine residue in II, III and IV while both the 1-valine and the 82-lysine are labelled in V and VI. Similarly, modification of the 1-valine residue of the alpha chains of IV and VI was detected. Components II and III have the same molecular formula. Evidence is presented which shows that they are interconvertible and that they correspond to the PLP2-Hb species and component V is Benesch's PLP4-Hb [J. Biol. Chem., 257 (1983) 1320 and references cited therein]. Component IV is III with one additional PLP per alpha chain and similarly VI is V with monolabelled alpha chains.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced coronary vasoconstrictor activity of hemoglobin solutions purified by ATP-agarose affinity chromatography.

Stroma-free hemoglobin (Hb) solutions are being developed as blood substitutes. We previously described coronary vasoconstrictor activity of Hb solutions prepared by conventional methods. In the present study we assessed the constrictor activity of unmodified and covalently modified Hb solutions purified by ATP-agarose affinity chromatography. The starting material was a red cell lysate, partially purified by ultrafiltration. Coronary constrictor activity was measured as increased perfusion pressure in isolated rabbit hearts perfused at constant coronary flow rate with buffer containing various concentrations of added Hb. The starting material increased perfusion pressure by 35 +/- 7 mmHg at 50 mg/dl. Purified Hb, retained by the affinity column, increased perfusion pressure by only 18 +/- 2 mmHg at 50 mg/dl. Hemoglobin covalently linked to ATP or pyridoxal phosphate, then purified by affinity chromatography, also had less constrictor activity than the starting material. Thus, a substance, removed by affinity chromatography but not by conventional purification, contributes to the vasoconstrictor activity of Hb solutions.

Isolation and partial characterization of pyridoxal 5'-phosphate hemoglobins by high-performance liquid chromatography as a quality-control method for hemoglobin-based blood substitutes.

Pyridoxal 5'-phosphate hemoglobin (PLP-Hb), prepared from hemoglobin and a four-fold excess of pyridoxal 5'-phosphate by the method of De Venuto and Zegna [J. Surg. Res., 34 (1983) 205], has been chromatographically resolved into six components via a quaternary ammonium monobead support. On an analytical scale, the separations have been found to be rapid (ca. 50 min) and highly reproducible. The results also indicate that the preparation of PLP-Hb yields a reproducible product ratio. The potential of the analytical method for the routine quality control of blood substitutes derived from PLP-Hb is discussed. All five of the PLP derivatives (components II-VI), isolated and purified via a combination of conventional and preparative monobead anion-exchange chromatography, gave single peaks when analyzed by high-performance liquid chromatography. Total phosphate analyses indicated that components II and III each contain two PLPs per Hb, IV and V four and VI six.