Safety Assessment of Hydroponic Closed System

The hydroponic system is an increasing sector for horticultural production. It is used mostly for fruit and vegetable production. Lettuce (Lactuca sativa) is one of the most cultivated types of produce in the hydroponic system. It runs on nutrient solution and in some cases substrates. Water serves as the backbone for hydroponic production, mainly utilized for nutrient solution preparation. Substrates are sometimes added to provide support for plants root systems. Selection of substrate depends on the type of crop and the availability of the substrate. A good substrate should be able to balance the oxygen - water ratio around the root system and have a high water retention ability. Peat moss is an organic substrate mostly used by growers due to its sustainability and additional ability to retain nutrients on its surface. The hydroponic system is classified as open or closed system depending on the nutrient solution usage. The closed system reuses spent nutrient solution and is economical with less water wastage. There is, however, a high rate of pathogen build-up in this system. The assurance of food security, food safety, and high yield has made the hydroponic system a widely accepted mode of production many vegetable horticultural commercial growers. Due to less to no contact of growing media to edible portions, the system is believed to provide a relatively safe, healthy, and clean product. However, the isolation of pathogens such as Salmonella, Eshericheria coli O157:H7, Listeria monocytogenes, and Campylobacter spp. from hydroponically grown crops has created awareness about the potential risk of foodborne illnesses from this system. Research is geared toward screening of source of irrigation water and other potential sources of contamination in the hydroponic production. However, little is known about the possible source of contamination in the hydroponic system. The objectives of this study were to: (i) identify possible sources of contamination in the hydroponic system; (ii) evaluate the efficacy of behavior modification and/or sanitization in the reduction of microbial count on harvested produce throughout expected shelf life; and (iii) evaluate the microbial load on different peat moss substrates as well as heat-treated peat moss substrates. Water, leaf, root, and substrate samples were collected from an actively growing, closed hydroponic system. Water samples included ‘water outlet’, ‘water inlet’, tap water and ‘water reservoir’. The leaf samples consisted of onsite leaf and harvested leaf while the substrates were onsite substrate and fresh substrate. Substrate used in this study was of peat moss origin. Samples were enumerated for aerobic plate count (APC), coliform bacteria (CB), and yeast and mold (YM). Detection of Listeria was carried out and none was detected on any of the samples. Enumerated count for all microbes was highest in the onsite substrate samples. Interestingly, onsite lettuce leaves had the lowest count for all counts. The harvested leaves were relatively higher in APC and YM count compare to the onsite leaves. The time of contact of the other samples with the onsite substrate significantly increased the microbial count on these samples, raising the possibility of the substrate being the source of contamination. Reduction in the microbial load on the substrate was carried out by combining sanitizers, storage time, and packaging method. Sanitizers consisted of chlorine (Cl-200 ppm), peroxyacetic acid (PAA-80 ppm), and sterile distilled water (SDW). Microbiological and sensory quality measures were carried out on harvested substrate (plug), roots, and leaves. The harvested lettuce maintained its appearance and color after sanitizer application. Storage time and sanitizer significantly reduced APC and yeast count. PAA was most effective against APC and YM while chlorine was effective against CB. Sensory quality measurement indicated that dipping the harvested lettuce substrate in a solution before packaging aided in maintaining the lettuce color and fresh appealing look. Other peat moss substrates and heat-treated substrates were examined for microbial populations. A difference in microbial load was found on substrates due to difference in rate of decomposition, chemical, and physical properties. Overall, this research shows that substrate is a possible source of contamination in the hydroponic closed system. This research demonstrates that sanitizer wash could effectively help reduce microbial load on lettuce leaves and different compositions of substrates influence their ability to host microbes

Review of catch trends and changes in fish species composition of the Volta lake during its 45 years of existence

Existing catch data for the whole of the Volta lake from 1969 to 2004 and those for certain segments of the lake (Strata II, III, and IV) covering various periods were analysed in relation to lake levels, to find out changes in catch trends and species composition. The study was undertaken as a baseline activity aimed at enhancing fisheries productivity and  management of the lake. Higher catches were made at the inception of the lake, with about 65,000 t being recorded in 1969. This dropped and  fluctuated between 36,000 anct48,000 t from 1971 to 1994. Catches kept increasing rapidly from 1995 with about 80,000 t being recorded in 1999, the highest in the history of the lake. In relation to annual fake water level fluctuations, high catches were made during periods of low water level compared to periods of high water level. On the long term, decreasing lake water level corresponded with higher fish catches. There was a change frominsectivorous fish species (e.g., Chrysichthys, Schilhe and Synodontis) at the initial stages of the formation of the lake to those with vegetarian food habits dominated by the tilapias. The dominance oftilapias in catches, which persisted till the early parts of the 1990s, has given way to Chrysichthys spp., suggesting that the composition of fish species in the lake is still undergoing changes 45 years after its formation

Improved fisheries productivity and management in tropical reservoirs

“Improved fisheries productivity and management in tropical reservoirs” The objective of the project was to contribute to the current research on reservoirs enhancement fisheries in tropical countries through the implementation of a series of action-research activities implemented in two small reservoirs in the Indo-Gangetic basin in India, and two very large reservoirs in Africa, the Lake Nasser (Egypt), and the Volta Lake (Ghana). Socio-institutional analyses were also conducted in these reservoirs to improve our knowledge regarding some of the main social processes that influence reservoir productivity. Overall the results of the project stress that while the natural biophysical constraints of the reservoirs are important in defining the ecological production processes, it is the socio-economic settings characterizing the community/societies around the reservoirs that eventually shape the human production enhancement possibilities

Autosomal dominant optic atrophy and cataract “plus” phenotype including axonal neuropathy

Objective To characterize the phenotype in individuals with OPA3-related autosomal dominant optic atrophy and cataract (ADOAC) and peripheral neuropathy (PN). Methods Two probands with multiple affected relatives and one sporadic case were referred for evaluation of a PN. Their phenotype was determined by clinical ± neurophysiological assessment. Neuropathologic examination of sural nerve and skeletal muscle, and ultrastructural analysis of mitochondria in fibroblasts were performed in one case. Exome sequencing was performed in the probands. Results The main clinical features in one family (n = 7 affected individuals) and one sporadic case were early-onset cataracts (n = 7), symptoms of gastrointestinal dysmotility (n = 8), and possible/confirmed PN (n = 7). Impaired vision was an early-onset feature in another family (n = 4 affected individuals), in which 3 members had symptoms of gastrointestinal dysmotility and 2 developed PN and cataracts. The less common features among all individuals included symptoms/signs of autonomic dysfunction (n = 3), hearing loss (n = 3), and recurrent pancreatitis (n = 1). In 5 individuals, the neuropathy was axonal and clinically asymptomatic (n = 1), sensory-predominant (n = 2), or motor and sensory (n = 2). In one patient, nerve biopsy revealed a loss of large and small myelinated fibers. In fibroblasts, mitochondria were frequently enlarged with slightly fragmented cristae. The exome sequencing identified OPA3 variants in all probands: a novel variant (c.23T>C) and the known mutation (c.313C>G) in OPA3. Conclusions A syndromic form of ADOAC (ADOAC+), in which axonal neuropathy may be a major feature, is described. OPA3 mutations should be included in the differential diagnosis of complex inherited PN, even in the absence of clinically apparent optic atrophy

StopCOVID cohort : An observational study of 3,480 patients admitted to the Sechenov University hospital network in Moscow city for suspected COVID-19 infection

© 2020 Oxford University Press. This is a pre-copyedited, author-produced PDF of an article accepted for publication in Clinical Infectious Diseases following peer review. The version of record is available online at: https://doi.org/10.1093/cid/ciaa1535.BACKGROUND: The epidemiology, clinical course, and outcomes of COVID-19 patients in the Russian population are unknown. Information on the differences between laboratory-confirmed and clinically-diagnosed COVID-19 in real-life settings is lacking. METHODS: We extracted data from the medical records of adult patients who were consecutively admitted for suspected COVID-19 infection in Moscow, between April 8 and May 28, 2020. RESULTS: Of the 4261 patients hospitalised for suspected COVID-19, outcomes were available for 3480 patients (median age 56 years (interquartile range 45-66). The commonest comorbidities were hypertension, obesity, chronic cardiac disease and diabetes. Half of the patients (n=1728) had a positive RT-PCR while 1748 were negative on RT-PCR but had clinical symptoms and characteristic CT signs suggestive of COVID-19 infection.No significant differences in frequency of symptoms, laboratory test results and risk factors for in-hospital mortality were found between those exclusively clinically diagnosed or with positive SARS-CoV-2 RT-PCR.In a multivariable logistic regression model the following were associated with in-hospital mortality; older age (per 1 year increase) odds ratio [OR] 1.05 (95% confidence interval (CI) 1.03 - 1.06); male sex (OR 1.71, 1.24 - 2.37); chronic kidney disease (OR 2.99, 1.89 - 4.64); diabetes (OR 2.1, 1.46 - 2.99); chronic cardiac disease (OR 1.78, 1.24 - 2.57) and dementia (OR 2.73, 1.34 - 5.47). CONCLUSIONS: Age, male sex, and chronic comorbidities were risk factors for in-hospital mortality. The combination of clinical features were sufficient to diagnoseCOVID-19 infection indicating that laboratory testing is not critical in real-life clinical practice.Peer reviewe

Learning from Poverty: Why Business Schools Should Address Poverty, and How They Can Go About It.

In the past few years, business schools have begun to address poverty issues in their teaching, learning and curricula. While this is a positive development, the arguments for reconfiguring educational programs to address such matters remain undeveloped, with much of the impetus for such endeavors rooted in calls for social responsibility in the United Nations Millennium Development Goals, the Social Compact, the Principles for Responsible Management Education and benchmarks such as ISO 26000. This article seeks to clarify the pedagogical grounds for integrating poverty issues in management education by examining the intellectual and personal development benefits of doing so. By critically examining four modes of business involvement in poverty reduction, the article shows how such initiatives can be used as intellectual lenses through which to view the complex and often paradoxical interconnections between socioeconomic and environmental systems. It is thus concluded that a consideration of poverty issues is not a marginal matter, but is key to grasping the 21st century complexities of global business and management

Integrated Optimization of Microbial and Chemical Compositon of Non-dairy Low Alchol Fermenteted Beverages (NDLAFB): Kombucha and Water Kefir

Kombucha and water kefir are non-dairy low alcohol fermented beverages (NDLAFB) that have gained acceptance among consumers. Production of these beverages requires starter cultures that are reused in the next production cycle via backslopping ad infinitum unless subjectively discontinued by the producer. A better understanding of the effects of repeated culture usage and culture preservation on the stability, viability, and reproducibility of these beverages will aid in standardizing production and homogeneity in the final products. This study aimed at (1) evaluating the relationship among culture composition and physicochemical composition of finished beverages; (2) determining the diversity and stability of microbial communities present in mixed culture systems and finished beverages; and (3) exploring preservation techniques and their effects on microbial stability, recovery, and survival rate after storage. For objective 1, kombucha and water kefir cultures were obtained from commercial and homebrewers and fermented. Samples of the finished beverages underwent microbial and physicochemical assays at 2 week increments for 12 weeks under refrigerated storage. For both beverages, microbial counts were relatively stable for lactic acid bacteria (LAB) and yeast across repeated cultures. However, the high microbial count did not directly correlate with the amount of metabolites produced. During storage time microbial counts declined. The physicochemical components had the highest variation across batches of repeated brewing. For objective 2, DNA of culture and beverage samples were subjected to Illumina amplicon sequencing of bacterial 16S rRNA and fungal ITS regions. The data suggested that the cultures were composed of higher microbial abundance and diversity relative to the beverage. Stability, diversity, and abundance changed with repeated culture usage in both culture and beverage. For objective 3, cultures with or without cryoprotectants were preserved by freezing, vacuum-drying, and freeze-drying. Samples were enumerated for LAB, yeast, and acetic acid bacteria (AAB) on day 1 and day 30 of storage. Unpreserved cultures had the highest count in both cultures. Freezing with cryoprotectant application resulted in a relatively similar microbial count as was observed in the unpreserved cultures This study serves as foundational knowledge to optimize the production and preservation of these fermented beverage products to improve human health