Fermentation of water kefir beverage containing Ziziphus jujuba Mill. syrup : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology, Massey University, Albany, New Zealand

The following Figures were removed for copyright reasons but may be accessed via the sources provided: Figures 2.3 (=Stadie et al., 2013 Fig 5); 2.4 (=Fiorda et al., 2017 Fig 3); 2.5 (=Reddy et al., 2008 Fig 1); 2.6 (=van Dijken et al., 1993 Fig 2); 2.7 (=Waldherr et al., 2010 Fig 2B); 2.8 (=Fiorda et al., 2017 Fig 4); & 2.9 (=Fiorda et al., 2017 Fig 5).Water kefir is a self-carbonated, low sugar beverage with a mildly sour taste fermented by a microbial multispecies of kefir dominated by lactic acid bacteria (LAB) and yeasts. The fermented beverage is popular due to its pleasant sensory characteristics and perceived health benefits. The presence of probiotics and antioxidants in the water kefir confer health benefits to consumers when consumed in sufficient amounts. The major antioxidant in jujube fruit is rutin which is related to the reducing of high-density lipoprotein cholesterol and fasting blood sugar in patients with diabetes mellitus. The fermented beverage (water kefir) is produced mainly at household and by small-scale artisans whereby sucrose is normally added as a source of carbon for the fermentation. Due to consumer demand for foods containing low calories and carbohydrates, there is an incentive to produce products with reduced amount of added sugar including fermented water kefir. Jujube contains a high amount of sugars. This study investigated the potential of using syrup extracted from Ziziphus jujuba Mill. (jujube) to partially replace added sucrose used for water kefir fermentation. Several water-bath methods were investigated for the extraction of the jujube syrup. The most efficient method consisted of 650 mL extraction water and the mixture (jujube and water) was extracted at 70°C. The syrup obtained by this method was subjected to further studies. Two concentrations of the jujube syrup (10%, 20%, v/v) and two fermentation temperatures (25°C, 27°C) were used for the jujube water kefir fermentation. Various analyses and measurements were conducted on the beverage during fermentation and storage (4°C). The beverages were analysed for sugar, acidity, antioxidants, titratable acid, while pH, colour, and total soluble solids were measured. Microbiological analyses of the beverages were also conducted. The beverages were subjected to sensory evaluation by an informal focus group and by consumer sensory panellists using a 9-point hedonic rating scale. The beverage with higher syrup concentration (%, v/v) contained higher total soluble solids and was darker than the sample containing a lower concentration of syrup (p0.05) were observed between the total soluble solids of the beverages fermented at 25°C and 27°C. The fermented (27°C) jujube water kefir beverage (2.5% organic raw sugar, w/v; 20% jujube syrup, v/v for stage 1 fermentation) with added jujube syrup (20% v/v) in stage 2 was selected as the most promising formulation by consumer sensory panellists. At the end of the fermentation (72 h), the selected beverage contained ethanol (3.37±0.13% v/v), sucrose (0.17±0.03% w/v), glucose (0.92±0.14% w/v), fructose (1.44±0.08% w/v), lactic acid (0.14±0.00% w/v), acetic acid (0.37±0.02% w/v), and rutin (6.26±0.16% w/v). The high concentration of ethanol may be attributed to the conversion of lactic acid into ethanol by the LAB. After storage for 21 days (4°C), yeast counts had decreased (p<0.05) while LAB counts had decreased by about one log. The concentrations of the sugars and acetic acid had decreased whereas the concentrations of ethanol, rutin and lactic acid increased. Meanwhile, the overall acceptability sensory scores of the beverage had decreased after storage for 21 days (4°C). The results of this study indicated the potential of producing a low sugar jujube water kefir using reduced added sugar and jujube syrup. However, more research is required to reduce the ethanol content of the beverage to meet the requirement for low alcohol product in New Zealand. Also, further research is required to improve the stability of the beverage during refrigerated storage

Cryptanalysis and improvement of an efficient certificateless signature scheme

In traditional digital signature schemes, certificates signed by a trusted party are required to ensure the authenticity of the public key. In Asiacrypt 2003, the concept of certificateless signature scheme was introduced. The advantage of certificate-less public key cryptography successfully eliminates the necessity of certificates in the traditional public key cryptography and simultaneously solves the inherent key escrow problem suffered in identity-based cryptography. Recently, Yap et al. proposed an efficient certificateless signature scheme and claimed that their scheme is existentially unforgeable in the random oracle model. In this paper, we show that the certificateless signature scheme proposed by Yap et al. is insecure against public key replacement attacks. Furthermore, we propose an improved certificateless signature scheme, which is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the random oracle model and provide the security proof of the proposed scheme

MUC1 and MUC16: critical for immune modulation in cancer therapeutics

The Mucin (MUC) family, a range of highly glycosylated macromolecules, is ubiquitously expressed in mammalian epithelial cells. Such molecules are pivotal in establishing protective mucosal barriers, serving as defenses against pathogenic assaults. Intriguingly, the aberrant expression of specific MUC proteins, notably Mucin 1 (MUC1) and Mucin 16 (MUC16), within tumor cells, is intimately associated with oncogenesis, proliferation, and metastasis. This association involves various mechanisms, including cellular proliferation, viability, apoptosis resistance, chemotherapeutic resilience, metabolic shifts, and immune surveillance evasion. Due to their distinctive biological roles and structural features in oncology, MUC proteins have attracted considerable attention as prospective targets and biomarkers in cancer therapy. The current review offers an exhaustive exploration of the roles of MUC1 and MUC16 in the context of cancer biomarkers, elucidating their critical contributions to the mechanisms of cellular signal transduction, regulation of immune responses, and the modulation of the tumor microenvironment. Additionally, the article evaluates the latest advances in therapeutic strategies targeting these mucins, focusing on innovations in immunotherapies and targeted drugs, aiming to enhance customization and accuracy in cancer treatments

Cryptanalysis on Two Certificateless Signature Schemes

Certificateless cryptography has attracted a lot of attention from the research community, due to its applicability in information security. In this paper, we analyze two recently proposed certificateless signature schemes and point out their security flaws. In particular, we demonstrate universal forgeries against these schemes with known message attacks

Preserving transparency and accountability in optimistic fair exchange of digital signatures

Optimistic fair exchange (OFE) protocols are useful tools for two participants to fairly exchange items with the aid of a third party who is only involved if needed. A widely accepted requirement is that the third party\u27s involvement in the exchange must be transparent, to protect privacy and avoid bad publicity. At the same time, a dishonest third party would compromise the fairness of the exchange and the third party thus must be responsible for its behaviors. This is achieved in OFE protocols with another property called accountability. It is unfortunate that the accountability has never been formally studied in OFE since its introduction ten years ago. In this paper, we fill these gaps by giving the first complete definition of accountability in OFE where one of the exchanged items is a digital signature and a generic (also the first) design of OFE where transparency and accountability coexist

Carbon Dioxide-Catalyzed Stereoselective Cyanation Reaction

© 2019 American Chemical Society.We report a Michael-type cyanation reaction of coumarins by using CO2 as a catalyst. The delivery of the nucleophilic cyanide was realized by catalytic amounts of CO2, which forms cyanoformate and bicarbonate in the presence of water. Under ambient conditions, CO2-catalyzed reactions afforded high chemo- A nd diastereoselectivity of β-nitrile carbonyls, whereas only low reactivities were observed under argon or N2. Computational and experimental data suggest the catalytic role of CO2, which functions as a Lewis acid, and a protecting group to mask the reactivity of the product, suppressing byproducts and polymerization. The utility of this convenient method was demonstrated by preparing biologically relevant heterocyclic compounds with ease11sciescopu

PAR6, A Potential Marker for the Germ Cells Selected to Form Primordial Follicles in Mouse Ovary

Partitioning-defective proteins (PAR) are detected to express mainly in the cytoplast, and play an important role in cell polarity. However, we showed here that PAR6, one kind of PAR protein, was localized in the nuclei of mouse oocytes that formed primordial follicles during the perinatal period, suggesting a new role of PAR protein. It is the first time we found that, in mouse fetal ovaries, PAR6 appeared in somatic cell cytoplasm and fell weak when somatic cells invaded germ cell cysts at 17.5 days post coitus (dpc). Meanwhile, the expression of PAR6 was observed in cysts, and became strong in the nuclei of some germ cells at 19.5 dpc and all primordial follicular oocytes at 3 day post parturition (dpp), and then obviously declined when the primordial follicles entered the folliculogenic growth phase. During the primordial follicle pool foundation, the number of PAR6 positive germ cells remained steady and was consistent with that of formed follicles at 3 dpp. There were no TUNEL (apoptosis examination) positive germ cells stained with PAR6 at any time studied. The number of follicles significantly declined when 15.5 dpc ovaries were treated with the anti-PAR6 antibody and PAR6 RNA interference. Carbenoxolone (CBX, a known blocker of gap junctions) inhibited the expression of PAR6 in germ cells and the formation of follicles. Our results suggest that PAR6 could be used as a potential marker of germ cells for the primordial follicle formation, and the expression of PAR6 by a gap junction-dependent process may contribute to the formation of primordial follicles and the maintenance of oocytes at the diplotene stage

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks

The United States COVID-19 Forecast Hub dataset

Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages