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2021 ◽  
Author(s):  
Wataru Ogura ◽  
Kouki Ohtsuka ◽  
Sachiko Matsuura ◽  
Takahiro Okuyama ◽  
Satsuki Matsushima ◽  
...  

Objective In Japan, healthcare workers (HCWs) are vaccinated against coronavirus disease (COVID-19) and other contagious viruses (measles, rubella, chickenpox, mumps, and hepatitis B) to prevent nosocomial infection. However, some do not produce sufficient antibodies after vaccination (low responders). This study investigated changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels among HCWs after SARS-CoV-2 vaccination and assessed whether low responders produced adequate SARS-CoV-2 anti-spike and neutralizing antibodies. Methods We conducted a prospective cohort study of HCWs before and after vaccination with the BNT162b2 mRNA vaccine in a hospital in Tokyo, Japan. The HCWs received two doses of BNT162b2 vaccine, 3 weeks apart. Those whose antibody levels against previous antiviral vaccines did not reach protective antibody levels after receiving two doses were defined as low responders, whereas those who produced adequate antibodies were defined as normal responders. SARS-CoV-2 anti-spike antibodies were measured 11 times from before the first BNT162b2 vaccination to 5 months after the second vaccination. SARS-CoV-2 neutralizing antibody activity was measured twice in low responders, 1 week to 1 month and 5 months after the second vaccination. Results Fifty HCWs were included in the analytic cohort. After vaccination, SARS-CoV-2 anti-spike antibody was detectable in the samples from both responders at each timepoint, but the level was lower at 5 months than at 1 week after the second vaccination. Low responders had SARS-CoV-2 neutralizing antibody activity 1 week to 1 month after the second vaccination, which exceeded the positive threshold after 5 months. Conclusion After BNT162b2 vaccination, low responders acquired adequate SARS-CoV-2 anti-spike and SARS-CoV-2 neutralizing antibodies to prevent SARS-CoV-2. However, SARS-CoV-2 anti-spike antibody levels were lower at 5 months than at 1 week after the second dose of BNT162b2 vaccine in low and normal responders. Therefore, low responders should also receive a third dose of BNT162b2 vaccine.


2021 ◽  
Author(s):  
Chandima Jeewandara ◽  
Inoka Aberathna ◽  
Saubhagya Danasekara ◽  
Laksiri Gomes ◽  
Suranga Fernando ◽  
...  

We assessed antibody responses 3 months post-vaccination in those who received mRNA-1273 (n=225), Sputnik V (n=128) or the first dose of Gam-COVID-Vac (n=184) and compared the results with previously reported data of Sinopharm and AZD1222 vaccinees. 99.5% of Moderna >94% of AZD1222 or Sputnik V, 72% to 76% of Gam-COVID-Vac (first dose) and 38.1% to 68.3% of Sinopharm vaccinees had ACE2 blocking antibodies above the positive threshold. The ACE2 blocking antibody levels were highest to lowest was Moderna > Sputnik V/ AZD1222 (had equal levels)> first dose of Gam-COVID-Vac > Sinopharm. All Moderna recipients had antibodies above the positive threshold to the ancestral (WT), B.1.1.7, B.1.351.1 and 80% positivity rate for B.1.617.2. Positivity rates of Sputnik V vaccinees for WT and variants, were higher than AZD1222 vaccinees, while Sinopharm vaccinees had the lowest positivity rates (<16.7%). These findings highlight the need for further studies to understand the effects on clinical outcomes.


Author(s):  
Matthew Johnson ◽  
Daniël Paulusma ◽  
Erik Jan van Leeuwen

Let [Formula: see text] be an integer. From a set of [Formula: see text]-dimensional vectors, we obtain a [Formula: see text]-dot by letting each vector [Formula: see text] correspond to a vertex [Formula: see text] and by adding an edge between two vertices [Formula: see text] and [Formula: see text] if and only if their dot product [Formula: see text], for some fixed, positive threshold [Formula: see text]. Dot product graphs can be used to model social networks. Recognizing a [Formula: see text]-dot product graph is known to be NP -hard for all fixed [Formula: see text]. To understand the position of [Formula: see text]-dot product graphs in the landscape of graph classes, we consider the case [Formula: see text], and investigate how [Formula: see text]-dot product graphs relate to a number of other known graph classes including a number of well-known classes of intersection graphs.


2021 ◽  
Vol 67 (4) ◽  
pp. 456-462
Author(s):  
Dmitrii Andreev ◽  
Asan Kashurnikov ◽  
Aleksandr Zavyalov

Introduction. According to WHO data for 2020, colorectal cancer occupies first (highest) position (excluding non-melanoma skin cancer) in the top ranking list of the most frequent cancers in the Russian Federation.  Colorectal cancer screening plays a pivotal role in early diagnosis and treatment. The best positive threshold values for hemoglobin concentration in a quantitative fecal immunochemical test (FIT) are postulated in a fraction of foreign recommendations. We reviewed the FIT cut-off values in those clinical guidelines. Materials and methods. The relevant publications were retrieved from PubMed and Google. The search horizon covered the last decade. Searches used the terms: «fecal immunochemical test» AND «screening» OR «cancer» AND «colorectal» OR «colon» OR «rectum", as well as other semantic and thematic forms. The recommendations appeared in last decade were reviewed. Results. This review summarizes the cut-off values for hemoglobin concentration in FIT, included in the clinical and laboratory guidelines developed in such regions as: Europe, Canada, USA, New Zealand. Many CRC screening programs use the FIT with a threshold setting for interpreting a positive test result. In practice, a wide range of options for threshold hemoglobin concentrations is used to interpret positive results of quantitative FIT. The FIT cut-off value is critically important to select the size of population for further examination depending on capacity of colonoscopy units. Discussion and conclusions. The foreign guidelines don’t establish single unified approach for FIT results interpretation, which would be an optimal fit for all imaginable practical situations in healthcare system. Improvement of screening techniques based on FIT would lead to the further steps on the way towards more effective and safe CRC diagnosis.


2021 ◽  
Vol 36 (6) ◽  
pp. 1239-1239
Author(s):  
Jeremy Davis ◽  
Gabrielle Hromas ◽  
Summer Rolin

Abstract Objective Classification accuracy of embedded performance validity tests (PVTs) is unknown in cases involving bilingual examinees evaluated in English. This study examined false positive rates in bilingual individuals in an older adult sample. Method The project involved secondary analysis of a deidentified dataset (N = 22,688) from the National Alzheimer’s Coordinating Center (NACC). Exclusion criteria were diagnosis of mild cognitive impairment (MCI; n = 5160) or dementia (n = 5550). The initial sample included 11,513 participants grouped as cognitively normal (89.6%) or impaired but not MCI. A subset of 275 participants was identified with a primary language other than English who were evaluated in English. Propensity score matching was conducted by diagnostic group to match bilingual to monolingual participants on age, education, gender, and MMSE score. The final sample included 450 and 100 participants in normal and impaired groups, respectively. Failure rates on five embedded PVTs in the NACC cognitive test battery were examined by language and by diagnosis. Results Age, education, gender, and MMSE score were not significantly different by language in either diagnostic group. In the normal group, 4.9% of bilingual and 2.2% of monolingual participants failed two or more PVTs (n.s.). In the impaired group, 12% of bilingual and 6% of monolingual participants failed two or more PVTs (n.s.). Conclusions PVT failure rates were not significantly different between bilingual participants evaluated in English and monolingual participants in either diagnostic group. Failure rates, however, increased slightly above a common false positive threshold of 10% in bilingual participants in the impaired group.


2021 ◽  
pp. 095646242110222
Author(s):  
Thomas Juniper ◽  
Chris P Eades ◽  
Eliza Gil ◽  
Harriet Fodder ◽  
Killian Quinn ◽  
...  

Objectives: An elevated serum (1-3)-β-D-glucan (BDG) concentration has high sensitivity for a diagnosis of Pneumocystis pneumonia (PCP) in people with HIV (PWH). At the current manufacturer-recommended positive threshold of 80 pg/mL (Fungitell), specificity for PCP is variable and other diagnostic tests are required. We evaluated the utility of serum BDG for diagnosis of suspected PCP in PWH at three inner-London hospitals to determine BDG concentrations for diagnosis and exclusion of PCP. Methods: From clinical case records, we abstracted demographic and clinical information and categorised patients as having confirmed or probable PCP, or an alternative diagnosis. We calculated sensitivity, specificity and positive predictive value (PPV) of serum BDG concentrations >400 pg/mL and negative predictive value (NPV) of BDG <80 pg/mL. Results: 76 patients were included; 29 had laboratory-confirmed PCP, 17 had probable PCP and 30 had an alternative diagnosis. Serum BDG >400 pg/mL had a sensitivity of 83%, specificity of 97% and PPV 97% for diagnosis of PCP; BDG <80 pg/mL had 100% NPV for exclusion of PCP. Conclusions: In PWH with suspected PCP, BDG <80 pg/mL excludes a diagnosis of PCP, whereas BDG concentrations >400 pg/mL effectively confirm the diagnosis. Values 80–400 pg/mL should prompt additional diagnostic tests.


2021 ◽  
pp. 002029402110218
Author(s):  
Takeshi Mizuno ◽  
Taku Egawa ◽  
Masaya Takasaki ◽  
Yuji Ishino

Mass measurement using relay feedback of velocity and restoring force compensation is investigated for determining the mass of an object under weightless conditions. In the measurement system, the velocity of the object is fed back through a relay with hysteresis and the force acting on the object is switched from a positive value to a negative value when the velocity reaches a positive threshold and vice versa. As a result, a limit cycle is induced in the measurement system and the mass is estimated based on the period of the limit cycle. In addition, restoring force compensation with a spring is introduced to avoid the drift of the trajectory. This compensation makes the static equilibrium state unique. However, the trajectory still drifts slightly. It causes some error in measurement when a simple formula of estimating mass is applied. To eliminate such an error, a new formula is derived to estimate the mass independently of the position of the trajectory that is determined by the switching positions in the relay actions. When the switching positions deflect from the origin at which the spring is in the natural length, the trajectory is not at the center and becomes asymmetric. It is analytically shown that the period of the limit cycle is minimum when the switching positions are at the origin. It indicates that mass is overestimated with the simple estimation formula when the trajectory is not at the center. The validity of the modified formula and the analytical results are confirmed experimentally.


World Affairs ◽  
2021 ◽  
Vol 184 (2) ◽  
pp. 176-212
Author(s):  
Simplice A. Asongu ◽  
Joseph Nnanna

This study assesses how globalization modulates the effect of governance on carbon dioxide (CO2) emissions in sub-Saharan African countries. The empirical evidence is based on Generalized Method of Moments. The minimum level (or negative threshold) of Foreign Direct Investment required for it to interact with political stability and contribute toward the green economy is 45 percent of gross domestic product (GDP), while 90 percent of GDP is the maximum level (or positive threshold) required for trade to complement “voice and accountability” in mitigating CO2 emissions. Seventy-six percent of GDP and 80 percent of GDP are, respectively, negative trade thresholds for government effectiveness and economic governance. The corresponding negative trade thresholds for the rule of law, corruption-control, and institutional governance are, respectively, 230 percent of GDP, 63.5 percent of GDP, and 106.5 percent of GDP. Actionable openness policy thresholds are provided to inform policy makers on how governance interacts with globalization to promote the green economy.


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