53 research outputs found
How natural is a small \bar\theta in left-right SUSY models ?
In the world without an axion the smallness of may be achieved
due to a spontaneously broken discrete left-right symmetry. We analyze the
radiatively induced \bar\theta in the context of generic left-right symmetric
SUSY models without assuming flavor degeneracy in the squark sector. Left-right
symmetry allows to keep \bar\theta within its present bound only if the
inter-generational mass splitting in the squark sector at the scale of the
left-right symmetry breaking is smaller than 0.5%. We also consider the
naturalness of m_u=0 solution to the strong CP problem in the context of
horizontal flavor symmetries. A strong bound on the combination of the
horizontal charges in the Up quark sector is found in this case.Comment: 12 pages, latex, 1 figure, references adde
Fermion Masses and Mixing in General Warped Extra Dimensional Models
We analyze fermion masses and mixing in a general warped extra dimensional
model, where all the Standard Model (SM) fields, including the Higgs, are
allowed to propagate in the bulk. In this context, a slightly broken flavor
symmetry imposed universally on all fermion fields, without distinction, can
generate the full flavor structure of the SM, including quarks, charged leptons
and neutrinos. For quarks and charged leptons, the exponential sensitivity of
their wave-functions to small flavor breaking effects yield naturally
hierarchical masses and mixing as it is usual in warped models with fermions in
the bulk. In the neutrino sector, the exponential wave-function factors can be
flavor-blind and thus insensitive to the small flavor symmetry breaking
effects, directly linking their masses and mixing angles to the flavor
symmetric structure of the 5D neutrino Yukawa couplings. The Higgs must be
localized in the bulk and the model is naturally more successful in generalized
warped scenarios where the metric background solution is different than
. We study these features in two simple frameworks, flavor
complimentarily, and flavor democracy, which provide specific predictions and
correlations between quarks and leptons, testable as more precise data in the
neutrino sector becomes available.Comment: 33 pages, 7 figure
The Structure and Control of Public Enterprises in Algeria: Problems and Reforms
The Algerian public enterprise which, since 1965, had benefitted from considerable political and financial support of policy makers came under closer scrutiny and, indeed, severe criticism in the late 1970's. In 1980 the central authorities decided to reorganise these public firms. This reorganisation was part of a wider reform programme aimed at restructuring the administration and management of the public sector as a whole. The reforms stressed the need for greater decentralisation in decision making and a greater degree of financial autonomy for the public enterprises. The public enterprises were broken up into smaller, more specialised units in order to allow a more rational use of resources and to reduce the widespread inefficiency and waste in the public sector. In addition to these structural changes the finances of the public enterprises were overhauled. A number of measures to strengthen their financial autonomy were proposed. These included the deregulation of prices, the reactivation of the role of credit, the introduction of self-financing for minor investments
Patterns in the Fermion Mixing Matrix, a bottom-up approach
We first obtain the most general and compact parametrization of the unitary
transformation diagonalizing any 3 by 3 hermitian matrix H, as a function of
its elements and eigenvalues. We then study a special class of fermion mass
matrices, defined by the requirement that all of the diagonalizing unitary
matrices (in the up, down, charged lepton and neutrino sectors) contain at
least one mixing angle much smaller than the other two. Our new parametrization
allows us to quickly extract information on the patterns and predictions
emerging from this scheme. In particular we find that the phase difference
between two elements of the two mass matrices (of the sector in question)
controls the generic size of one of the observable fermion mixing angles: i.e.
just fixing that particular phase difference will "predict" the generic value
of one of the mixing angles, irrespective of the value of anything else.Comment: 29 pages, 3 figures, references added, to appear in PR
Analog In-Memory Computing with Uncertainty Quantification for Efficient Edge-based Medical Imaging Segmentation
This work investigates the role of the emerging Analog In-memory computing
(AIMC) paradigm in enabling Medical AI analysis and improving the certainty of
these models at the edge. It contrasts AIMC's efficiency with traditional
digital computing's limitations in power, speed, and scalability. Our
comprehensive evaluation focuses on brain tumor analysis, spleen segmentation,
and nuclei detection. The study highlights the superior robustness of isotropic
architectures, which exhibit a minimal accuracy drop (0.04) in analog-aware
training, compared to significant drops (up to 0.15) in pyramidal structures.
Additionally, the paper emphasizes IMC's effective data pipelining, reducing
latency and increasing throughput as well as the exploitation of inherent noise
within AIMC, strategically harnessed to augment model certainty
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.
Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Sputum Interleukin-32 in childhood asthma: correlation with IL-1β
_Background:_ Asthma is an airway disorder where inflammatory cytokines are partly responsible for exacerbating the disease. Interleukin (IL)-32, generally referred to as natural killer cell (NK4) transcript 4, is described as an immunoregulator involved in the stimulation of anti-/pro-inflammatory cytokines. The abnormal presence of IL-32 has been observed during inflammatory diseases, particularly in asthma. This study aims to characterize IL-32 in the inflammatory process in patients with severe asthma. _Methods:_ IL-32 and IL-1β levels in the supernatant of induced sputum obtained from 59 asthma patients (mild: 20 patients; moderate: 20 patients; severe: 19 patients) were measured using ELISA. Sputum IL-32 mRNA expression was measured by RT- PCR. _Results:_ Sputum IL-32 was significantly elevated at the protein (_p= 0.00019_) and mRNA expression (_p < 0.0001_) in asthmatics compared to non-asthmatic controls. IL-32 was elevated in severe asthmatic patients (_p < 0.0001_) compared to mild-moderate asthma. Severe asthmatics allergic to house dust mites expressed higher sputum IL-32 level than severe asthmatics without allergy (_p = 0.0001_). A significant association was found between sputum IL-32 and IL-32 mRNA (r =0.531_; p = 0.0159_) in severe asthma. In the same way, sputum IL-1β and IL-32 were significantly correlated (r = 0.476; _p = 0.0337_). _Conclusion:_ The level of IL-32 in induced sputum may be associated with asthma severity.
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