A longitudinal study on the impact of high-altitude hypoxia on perceptual processes

This study aimed to explore the neural mechanisms underlying high-altitude (HA) adaptation and deadaptation in perceptual processes in lowlanders. Eighteen healthy lowlanders were administered a facial S1-S2 matching task that included incomplete face (S1) and complete face (S2) photographs combined with ERP technology. Participants were tested at four time points: shortly before they departed the HA (Test 1), twenty-five days after entering the HA (Test 2), and one week (Test 3) and one month (Test 4) after returning to the lowlands. Compared with those at sea level (SL), shorter reaction times (RTs), shorter latencies of P1 and N170, and larger amplitudes of complete face N170 were found in HAs. After returning to SL, compared with that of HA, the amplitude of the incomplete face P1 was smaller after one week, and the complete face was smaller after one month. The right hemisphere N170 amplitude was greater after entering HA and one week after returning to SL than at baseline, but it returned to baseline after one month. Taken together, the current findings suggest that HA adaptation increases visual cortex excitation to accelerate perceptual processing. More mental resources are recruited during the configural encoding stage of complete faces after HA exposure. The perceptual processes affected by HA exposure are reversible after returning to SL, but the low-level processing stage differs between incomplete and complete faces due to neural compensation mechanisms. The configural encoding stage in the right hemisphere is affected by HA exposure and requires more than one week but less than one month to recover to baseline.

Predicting high quality of participation in adaptive snow-sports for individuals with disabilities: An exploratory study

OBJECTIVES

This exploratory study aimed to examine the individual, program and environmental (social and physical) characteristics which predict high quality of participation in adaptive snowsports for each dimension of the Quality of Participation in Parasport Framework (QPPF): autonomy, belongingness, mastery, challenge, engagement and meaning.

METHODS

A survey was completed by 133 individuals with disabilities or their representatives on each dimension of the QPPF in adaptive snowsports and on the factors impacting the quality of participation. Descriptive statistics were used to describe the study participants, and a multivariate logistic regression model was constructed for each dimension of the QPPF to evaluate the relative contribution of individual, snowsport-related, program and environmental factors to each dimension.

RESULTS

Individuals with disabilities in this study reported high quality of participation on all dimensions of the QPPF. The individual characteristics only predicted the QPPF dimension of challenge. However, the program and environmental characteristics such as equipment, number of instructors and barriers were robust predictors of quality of participation.

CONCLUSION

Overall, participants experienced high quality participation. Supporting the adaptive snowsports programs while reducing the barriers faced by people with disabilities should be a continued effort to promote quality of participation.

The change of attention network functions and physiological adaptation during high-altitude hypoxia and reoxygenation

Previous studies have not reached a definitive conclusion regarding the effect of high-altitude hypoxia and reoxygenation on attention. To clarify the influence of altitude and exposure time on attention and the relations between physiological activity and attention, we conducted a longitudinal study to track attention network functions in 26 college students. The scores on the attention network test and physiological data, including heart rate, percutaneous arterial oxygen saturation (SpO₂), blood pressure, and vital capacity in pulmonary function measurement, were collected at five time-points: two weeks before arriving at high altitude (baseline), within 3 days after arriving at high altitude (HA3), 21 days after arriving at high altitude (HA21), 7 days after returning to sea level (POST7) and 30 days after returning to sea level (POST30). The alerting scores at POST30 were significantly higher than those at baseline, HA3 and HA21; the orienting scores at HA3 were lower than those at POST7 and POST30; the executive control scores at POST7 were significantly lower than those at baseline, HA3, HA21, and POST30; and the executive control scores at HA3 were significantly higher than those at POST30. The change in SpO₂ during high-altitude acclimatization (from HA3 to HA21) was positively correlated with the orienting score at HA21. Vital capacity changes during acute deacclimatization positively correlated with orienting scores at POST7. Attention network functions at the behavioral level did not decline after acute hypoxia exposure compared with baseline. Attention network functions after returning to sea level were improved compared with those during acute hypoxia; additionally, alerting and executive function scores were improved compared with those at baseline. Thus, the speed of physiological adaptation could facilitate the recovery of orienting function during acclimatization and deacclimatization.

Attention Network Changes of High-Altitude Migrants

INTRODUCTION: The present study aimed to explore whether there are changes in the alerting, orienting, and executive network efficiencies of attention function between high altitude immigrants and low altitude residents.METHODS: Event-related potentials (ERP) were acquired during an attention network test (ANT). The high-altitude (HA) group comprised 22 college student immigrants who were born and raised at low altitudes and had lived at a HA (11,975 ft/3650 m) for 26 mo (tests were conducted when they returned to HA for 3 mo). The low-altitude (LA) group comprised 23 college students who had never visited HA areas before.RESULTS: Compared with the LA group, the HA group had a higher pulse rate, lower oxygen saturation level, and decreased alerting and orienting effects in the behavioral results. The ERP results of the HA group showed a smaller P1 in the occipital area, a larger N1 both in the parietal and occipital areas of the alerting network, and a smaller P1 and larger N1 in the orienting network than the LA group. In the executive control network, the N2 amplitude of the HA group was more negative and the P3 amplitude of the HA group decreased in incongruent conditions.DISCUSSION: Together, these findings suggest that high-altitude migrants are less effective at alerting and orienting than low-altitude residents. For executive control function, changes in the P3 amplitudes of incongruent conditions indicated a decrease in conflict inhibition underlying the executive-control network.An X, Tao G, Zhang X, Ma H, Wang Y. Attention network changes of high-altitude migrants. Aerosp Med Hum Perform. 2022; 93(11):791–799.

Performance improvement of wastewater treatment processes by application of machine learning

Improving wastewater treatment processes is becoming increasingly important, due to more stringent effluent quality requirements, the need to reduce energy consumption and chemical dosing. This can be achieved by applying artificial intelligence. Machine learning is implemented in two domains: (1) predictive control and (2) advanced analytics. This is currently being piloted at the integrated validation plant of PUB, Singapore's National Water Agency. (1) Primarily, predictive control is applied for optimised nutrient removal. This is obtained by application of a self-learning feedforward algorithm, which uses load prediction and machine learning, fine-tuned with feedback on ammonium effluent. Operational results with predictive control show that the load prediction has an accuracy of ≈88%. It is also shown that an up to ≈15% reduction of aeration amount is achieved compared to conventional control. It is proven that this load prediction-based control leads to stable operation and meeting effluent quality requirements as an autopilot system. (2) Additionally, advanced analytics are being developed for operational support. This is obtained by application of quantile regression neural network modelling for anomaly detection. Preliminary results illustrate the ability to autodetect process and instrument anomalies. These can be used as early warnings to deliver data-driven operational support to process operators.

Novel poly (ADP-ribose) polymerase inhibitor, AZD2281, enhances radiosensitivity of both normoxic and hypoxic esophageal squamous cancer cells

Radiotherapy plays an important role in the treatment of esophageal squamous cell carcinoma (ESCC). However, the outcome of radiotherapy in ESCC remains unsatisfactory because esophageal squamous cancer cells, particularly those under hypoxic condition, exhibit radioresistance. The aim of this study was to determine whether or not AZD2281, a potent poly (ADP-ribose) polymerase (PARP) inhibitor, could enhance the radiation sensitivity of two ESCC cell lines, namely ECA109 and TE13. The radiosensitizing effect of AZD2281 was evaluated on the basis of cell death, clonogenic survival and tumor xenograft progression. AZD2281 alone was slightly toxic to ESCC cell lines. Apoptosis was increased and clonogenic survival was decreased in both cell lines when AZD2281 was combined with ionizing radiation (IR) under normoxic condition. AZD2281 enhanced IR-induced apoptosis to a more significant level under chronic hypoxic condition (0.2% O(2), 48 hour) than under normoxic condition. AZD2281 also slightly enhanced clonogenic cell death under chronic hypoxic condition compared with that under normoxic condition. This result could be associated with increased radiation-induced DNA double-strand breaks (DSB), decreased DSB repair and increased apoptosis of ESCC cells. Furthermore, homologous recombination (HR) protein Rad51 expression and focus formation were decreased in ESCC cells exposed to moderate chronic hypoxic condition (0.2% O(2), 48 hour); this result indicated that chronic hypoxic ESCC cells were HR deficient, possibly causing contextual synthetic lethality with PARP inhibitor in radiation sensitization. AZD2281 was also a radiation sensitizer in ESCC tumor xenograft models. Hence, in vitro and in vivo findings provide evidence that AZD2281 potently sensitizes ESCC cells to X-ray irradiation. The selective cell killing of HR-defective hypoxic cells contributes to radiosensitization by PARP inhibitor in ESCC cells under hypoxic condition.

Sexual behaviour and desire to discuss mental health as reported by HIV-infected men who have sex with men

We assessed sexually transmitted infection risk behaviours and desire to discuss mental health, as reported by 426 HIV-infected men who have sex with men receiving HIV care in eight urban clinics. Most of these patients (90%) had begun HIV care >1 year ago. In the past year, 74% had multiple sexual partners, 75% engaged in anal intercourse, 48% had >1 HIV-uninfected partner and 82% used illegal psychoactive drugs. Among those reporting anal intercourse, approximately 61% reported using a condom during the most recent episode. Among all patients, 70% wanted to talk with their clinicians about how they felt mentally or emotionally. Using a two-tailed chi-squared test, we found that patients who engaged in unprotected receptive anal sex were more likely to want such a conversation than those who did not (80% versus 62%, P < 0.01); and those who engaged in unprotected insertive anal sex were also more likely to want such a conversation (81% versus 63%, P < 0.01). The findings highlight the prevalence of risky sexual behaviour and of mental health concerns in the participating patient population. Patients reporting risky sexual behaviour were more likely to want to discuss how they felt mentally or emotionally than those not reporting such behaviour.

A retrospective study of different treatments of limited-stage small-cell esophageal carcinoma and associated prognostic factor analysis

Primary, small-cell esophageal carcinoma (SCEC) is a rare but highly malignant tumor. Due to lack of randomized, controlled, prospective studies, there are currently no unified treatment modalities for SCEC. This study retrospectively analyzed the outcomes of different treatments and prognostic factors that influence overall survival in patients with limited-stage SCEC. The study included 106 patients pathologically diagnosed with limited-stage SCEC at Huai'an First People's Hospital, Nanjing Medical University (Huai'an, China), between 1998 and 2007. There were 66 males and 40 females, with a median age of 58 years (range: 45-77 years). Fourteen patients received surgery alone, 42 received surgery and postoperative chemotherapy, 11 received radiotherapy alone, and 39 received concurrent chemoradiotherapy. Combined modality treatment with and without chemotherapy yielded 5-year survival rates (5YSRs) of 27.2% and 0%, respectively. Associated median survival times were 22 months and 11 months, respectively, with a hazard ratio (HR) of 2.30 (95% confidence interval [CI]: 1.42-3.73, P = 0.001). Among patients treated with surgery plus postoperative chemotherapy or with concurrent chemoradiotherapy, the 5YSRs were 31.0% and 23.1%, respectively. Median survival times were 26 months and 18 months, with an HR of 1.25 (95% CI: 0.75-2.09, P = 0.725). Multivariate survival analysis using Cox regression model showed that chemotherapy was a positive independent prognostic factor for SCEC (HR 2.92, 95% CI: 1.25-6.80). Chemotherapy-based combined modality treatment appears to increase the long-term survival of patients with limited-stage SCEC. Similar overall survival rates results are achieved with surgery combined with chemotherapy as with concurrent chemoradiotherapy, with chemotherapy being an independent prognostic factor. Randomized, controlled, prospective studies are needed to identify optimal chemotherapy regimens for treating SCEC.

The lymph index: a potential hematological parameter for viral infection

OBJECTIVE

An LH750 hematology analyzer with VCS (volume, conductivity, and light scatter) technology can determine morphologic properties of peripheral leukocytes, known as cell population data (CPD). We have previously demonstrated that the lymphocyte CPD exhibit significant changes in acute hepatitis B virus infection. A simplified lymphocyte CPD, the lymph index, was proposed. We conducted the current study to further evaluate the clinical usefulness of the lymph index, and included patients with various viral infections, as well as those with acute bacterial infections.

METHODS

Peripheral blood was collected from 72 patients with viral infections, 46 patients with acute bacterial infections, and 204 controls. The lymphocyte CPD included the mean volume (LV) with its standard deviation (LV-SD) and the conductivity (LC). The lymph index was calculated as LV × LV-SD ÷ LC.

RESULTS

The lymph index was significantly increased in viral infections and only mildly increased in acute bacterial infections compared to controls. Using a lymph index cutoff value of ≥ 12.92, we achieved 91.67% sensitivity and 97.2% specificity for diagnosing viral infection.

CONCLUSIONS

The findings may be clinically useful since these morphological parameters are readily obtained by hematology analyzer during automated leukocyte differentials. They are quantitative, objective, and fast. The lymph index could be a potential hematological parameter for viral infection.

Species-specific real-time PCR detection of Colletotrichum kahawae

AIMS

Colletotrichum kahawae is a strongly aggressive pathogen causing coffee berry disease and is specific to Arabica coffee (Coffea arabica) in Africa. In this article, we developed a real-time PCR assay for the species-specific diagnosis of C. kahawae by designing the primers and a TaqMan probe derived from the single nucleotide polymorphism-rich region of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene.

METHODS AND RESULTS

DNA markers from rDNA internal transcribed spacer, actin, β-tubulin and GAPDH genes of the ex-type culture of C. kahawae and 10 reference strains of Colletotrichum species were analysed for intra- and interspecific variations. The GAPDH gene was selected to develop a species-specific DNA marker. A TaqMan real-time PCR assay for species-specific detection of C. kahawae was developed, and its accuracy was tested against type strains of other phylogenetically closely related species in the C. gloeosporioides species complex, with the detection sensitivity of 80 fg μl(-1) of genomic DNA.

CONCLUSIONS

This real-time PCR assay is highly specific and sensitive for the diagnosis of C. kahawae and can be applied in qualitative and quantitative tests.

SIGNIFICANCE AND IMPACT OF THE STUDY

This protocol allows for a rapid and sensitive detection of C. kahawae and will be useful in disease management and pest detection to prevent further spread of this pathogen.

Seroprevalence of herpes simplex virus 2 among Hispanics in the USA: National Health and Nutrition Examination Survey, 2007-2008

To examine the seroprevalence of herpes simplex virus type 2 (HSV-2) among Hispanics in the USA, we used the cross-sectional, nationally representative National Health and Nutrition Examination Survey to compare the seroprevalence of HSV-2 between Hispanic persons of Mexican heritage and non-Mexican heritage aged 14-44 years, from survey years 2007-2008. The overall HSV-2 seroprevalence among Hispanics aged 14-44 years was 17.5% (95% confidence interval [CI], 15.2, 20.1) in the USA. HSV-2 seroprevalence was significantly lower among Mexican Americans than among other Hispanics (11.7% vs. 27.8%, P < 0.01). Prevalence of HSV-2 was also significantly associated with gender and age. The significant difference in HSV-2 seroprevalence between Hispanic persons of Mexican heritage and non-Mexican heritage suggested that targeting specific subgroups of Hispanics for preventive interventions may be a strategy to reduce the transmission of HSV-2 and HIV among Hispanics in the USA.

Hemodynamic monitoring in pigs undergoing orthotopic abdominal multivisceral transplantation

Anesthesia for abdominal multivisceral transplantation (MVTx) is challenging. Surgical success depends on hemodynamic stability throughout organ removal from the donor and engraftment in recipients. The aim of the current study was to summarize our experience with anesthetic management including monitoring of hemodynamic changes in pigs during MVTx procedures.

MATERIALS AND METHODS

Ten male pigs were randomly divided into two groups: donors and recipients for five MVTxs. A pulmonary artery catheter (PAC), transesophageal echocardiography (TEE), and pulse indicator continuous cardiac output (PiCCO) were used intraoperatively in recipients to monitor hemodynamic changes.

RESULTS

Two recipients had cardiac arrest and died intraoperatively presumably due to hypovolemia. The data obtained by PAC and TEE from three successful cases showed huge changes in hemodynamics during the stages of organ removal and reperfusion after engraftment. Use of PiCOO in one of those three cases allowed successful fluid management, resulting in stable intraoperative hemodynamics.

CONCLUSION

The anesthetic management for MVTx surgery was improved by PAC, TEE, and PiCOO monitoring.

Absence of donor-derived zona pellucida protein C homolog in the inner perivitelline layer of Peking duck (Anas platyrhynchos)-Japanese quail (Coturnix coturnix japonica) chimeras (Duails)

Avian blastodermal cells at stage X are used to produce interspecies chimeras for heterogenous poultry reproduction. However, recipient-derived inner perivitelline layer (IPVL)-enclosed donor-derived ova may affect the efficiency of germline transmission via chimera. Among the proteins in the IPVL, zona pellucida protein C (ZPC) plays an important role in sperm-egg binding and inducing the acrosome reaction. In the present study, Peking duck blastodermal cells at stage X were transferred into subgerminal cavities of Japanese quail embryos at the same stage. Fourteen female duck-quail chimeras (duails) were hatched and raised to sexual maturity. After being screened by PCR, 3 duails were selected for examination of donor-derived ZPC. A total of 152 IPVL protein samples from the individual eggs laid by the 3 duails then underwent a preliminary examination for the presence of donor-derived ZPC by means of SDS-PAGE, periodic acid-Schiff staining, and Western blotting. A novel 35-kDa ZPC, not observed in quail but in duck, was found in the IPVL of the duails. Further analysis of peptide mass fingerprinting of Peking duck ZPC, Japanese quail ZPC, and the 35-kDa duail ZPC by matrix-assisted laser desorption-ionization reflectron time-of-flight mass spectrometry revealed that the novel ZPC was an isoform of quail ZPC. Moreover, comparison of N-terminal amino acid sequences of these 3 ZPC confirmed that the 35-kDa quail ZPC had more amino acids at the N terminus than did native quail ZPC, and none of the donor-derived ZPC was found in the duails. These findings suggest that it would be difficult to obtain donor-derived offspring by natural mating of interspecies chimeras.

Treatment of RO brine-towards sustainable water reclamation practice

Treatment and disposal of RO brine is an important part in sustaining the water reclamation practice. RO brine generated from water reclamation contains high concentration of organic and inorganic compounds. Cost-effective technologies for treatment of RO brine are still relatively unexplored. Thus, this study aim to determine a feasible treatment process for removal of both organic and inorganic compounds in RO brine generated from NEWater production. The proposed treatment consists of biological activated carbon (BAC) column followed by capacitive deionization (CDI) process for organic and inorganic removals, respectively. Preliminary bench-scale study demonstrated about 20% TOC removal efficiency was achieved using BAC at 40 mins empty bed contact time (EBCT) while the CDI process was able to remove more than 90% conductivity reducing it from 2.19 mS/cm to only about 164 microS/cm. More than 90% cations and anions in the BAC effluent were removed using CDI process. In addition, TOC and TN removals of 78% and 91%, respectively were also attained through this process. About 90% water recovery was achieved. This process shows the potential of increased water recovery in the reclamation process while volume for disposal can be further minimized. Further studies on the sustainable operation and process optimization are ongoing.