286 research outputs found
CMB Signals of Neutrino Mass Generation
We propose signals in the cosmic microwave background to probe the type and
spectrum of neutrino masses. In theories that have spontaneous breaking of
approximate lepton flavor symmetries at or below the weak scale, light
pseudo-Goldstone bosons recouple to the cosmic neutrinos after nucleosynthesis
and affect the acoustic oscillations of the electron-photon fluid during the eV
era. Deviations from the Standard Model are predicted for both the total energy
density in radiation during this epoch, \Delta N_nu, and for the multipole of
the n'th CMB peak at large n, \Delta l_n. The latter signal is difficult to
reproduce other than by scattering of the known neutrinos, and is therefore an
ideal test of our class of theories. In many models, the large shift, \Delta
l_n \approx 8 n_S, depends on the number of neutrino species that scatter via
the pseudo-Goldstone boson interaction. This interaction is proportional to the
neutrino masses, so that the signal reflects the neutrino spectrum. The
prediction for \Delta N_nu is highly model dependent, but can be accurately
computed within any given model. It is very sensitive to the number of
pseudo-Goldstone bosons, and therefore to the underlying symmetries of the
leptons, and is typically in the region of 0.03 < \Delta N_nu < 1. This signal
is significantly larger for Majorana neutrinos than for Dirac neutrinos, and,
like the scattering signal, varies as the spectrum of neutrinos is changed from
hierarchical to inverse hierarchical to degenerate.Comment: 40 pages, 4 figure
Mini Z' Burst from Relic Supernova Neutrinos and Late Neutrino Masses
In models in which neutrinos are light, due to a low scale of symmetry
breaking, additional light bosons are generically present. We show that the
interaction between diffuse relic supernova neutrinos (RSN) and the cosmic
background neutrinos, via exchange of these light scalars, can result in a
dramatic change of the supernova (SN) neutrinos flux. Measurement of this
effect with current or future experiments can provide a spectacular direct
evidence for the low scale models. We demonstrate how the observation of
neutrinos from SN1987A constrains the symmetry breaking scale of the above
models. We also discuss how current and future experiments may confirm or
further constrain the above models, either by detecting the ``accumulative
resonance'' that diffuse RSN go through or via a large suppression of the flux
of neutrinos from nearby < O(Mpc) SN bursts.Comment: 24 pages, 8 figures, version to be published in JHE
The LHC Phenomenology of Vectorlike Confinement
We investigate in detail the LHC phenomenology of "vectorlike confinement",
where the Standard Model is augmented by a new confining gauge interaction and
new light fermions that carry vectorlike charges under both the Standard Model
and the new gauge group. If the new interaction confines at the TeV scale, this
framework gives rise to a wide range of exotic collider signatures such as the
production of a vector resonance that decays to a pair of collider-stable
charged massive particles (a "di-CHAMP" resonance), to a pair of
collider-stable massive colored particles (a "di-R-hadron resonance), to
multiple photons, s and s via two intermediate scalars, and/or to
multi-jet final states. To study these signals at the LHC, we set up two
benchmark models: one for the di-CHAMP and multi-photon signals, and the other
for the di-R-hadron and multijet signals. For the di-CHAMP/multi-photon model,
Standard Model backgrounds are negligible, and we show that a full
reconstruction of the spectrum is possible, providing powerful evidence for
vectorlike confinement. For the di-R-hadron/multijet model, we point out that
in addition to the di-R-hadron signal, the rate of the production of four
R-hadrons can also be sizable at the LHC. This, together with the multi-jet
signals studied in earlier work, makes it possible to single out vectorlike
confinement as the underlying dynamics.Comment: 32 pages, 28 figures. Several typos fixed, one paragraph added
elaborating choice of benchmarks. Version accepted by JHEP
Abnormalities of the FHIT gene in human oral carcinogenesis
The abnormalities of the fragile histidine triad (FHIT) gene in tissue samples of oral squamous cell carcinomas (SCCs) along with several leukoplakias and an erythroplakia were examined to determine whether the FHIT gene is actually a frequent target in vivo for alteration during oral carcinogenesis. Abnormal transcripts of the FHIT gene were found in eight of 15 oral SCCs. Although these abnormal transcripts varied widely, deletion patterns incorporating a deletion of exon 5 were the most common. Loss of heterozygosity (LOH) analysis demonstrated that the abnormal FHIT transcripts found in cancer cells were attributable to abnormalities of the FHIT gene. Abnormal FHIT transcripts were also observed in two of seven premalignant lesions. Interestingly, in the case of one patient with a premalignant lesion showing an abnormal FHIT transcript, subsequent oral SCC developed during a 3-year follow-up period. On the other hand, in the two patients from whom both leukoplakia and SCC samples were taken simultaneously, abnormal FHIT transcripts were found only in the SCCs. Although the functional role of FHIT remains to be clarified, these results suggest that the FHIT alteration is actually involved in carcinogenesis of the oral epithelium. © 2000 Cancer Research Campaig
Changes in utilization of health services among poor and rural residents in Uganda: are reforms benefitting the poor?
Exploring new health markets: experiences from informal providers of transport for maternal health services in Eastern Uganda
<p>Abstract</p> <p>Background</p> <p>Although a number of intermediate transport initiatives have been used in some developing countries, available evidence reveals a dearth of local knowledge on the effect of these rural informal transport mechanisms on access to maternal health care services, the cost of implementing such schemes and their scalability. This paper, attempts to provide insights into the functioning of the informal transport markets in facilitating access to maternal health care. It also demonstrates the role that higher institutions of learning can play in designing projects that can increase the utilization of maternal health services.</p> <p>Objectives</p> <p>To explore the use of intermediate transport mechanisms to improve access to maternal health services, with emphasis on the benefits and unintended consequences of the transport scheme, as well as challenges in the implementation of the scheme.</p> <p>Methods</p> <p>This paper is based on the pilot phase to inform a quasi experimental study aimed at increasing access to maternal health services using demand and supply side incentives. The data collection for this paper included qualitative and quantitative methods that included focus group interviews, review of project documents and facility level data.</p> <p>Results</p> <p>There was a marked increase in attendance of antenatal, and delivery care services, with the contracted transporters playing a leading role in mobilizing mothers to attend services. The project also had economic spill-over effects to the transport providers, their families and community generally. However, some challenges were faced including difficulty in setting prices for paying transporters, and poor enforcement of existing traffic regulations.</p> <p>Conclusions and implications</p> <p>The findings indicate that locally existing resources such as motorcycle riders, also known as “boda boda” can be used innovatively to reduce challenges caused by geographical inaccessibility and a poor transport network with resultant increases in the utilization of maternal health services. However, care must be taken to mobilize the resources needed and to ensure that there is enforcement of laws that will ensure the safety of clients and the transport providers themselves.</p
Bone pain induced by multiple myeloma is reduced by targeting V-ATPase and ASIC3
Multiple myeloma (MM) patients experience severe bone pain (MMBP) that is undertreated and poorly understood. In this study, we studied MMBP in an intratibial mouse xenograft model which employs JJN3 human MM cells. In this model, mice develop MMBP associated in bone with increased sprouting of calcitonin gene-related peptide-positive (CGRP+) sensory nerves and in dorsal root ganglia (DRG) with upregulation of phosphorylated ERK1/2 (pERK1/2) and pCREB, two molecular indicators of neuron excitation. We found that JJN3 cells expressed a vacuolar proton pump (V-ATPase) that induced an acidic bone microenvironment. Inhibition of JJN3-colonized bone acidification by a single injection of the selective V-ATPase inhibitor, bafilomycin A1, decreased MMBP, CGRP+ SN sprouting, and pERK1/2 and pCREB expression in DRG. CGRP+ sensory nerves also expressed increased levels of the acid-sensing nociceptor ASIC3. Notably, a single injection of the selective ASIC3 antagonist APETx2 dramatically reduced MMBP in the model. Mechanistic investigations in primary DRG neurons co-cultured with JJN3 cells showed increased neurite outgrowth and excitation inhibited by bafilomycin A1 or APETx2. Further, combining APETx2 with bafilomycin A1 reduced MMBP to a greater extent than either agent alone. Lastly, combining bafilomycin A1 with the osteoclast inhibitor zoledronic acid was sufficient to ameliorate MMBP which was refractory to zoledronic acid. Overall, our results show that osteoclasts and MM cooperate to induce an acidic bone microenvironment that evokes MMBP as a result of the excitation of ASIC3-activated sensory neurons. Further, they present a mechanistic rationale for targeting ASIC3 on neurons along with the MM-induced acidic bone microenvironment as a strategy to relieve MMBP in patients
Proposal of a decentralized peristaltic movement generation based on actual intestines and verification by content transfer experiment
Building partnerships towards strengthening Makerere University College of Health Sciences: a stakeholder and sustainability analysis
<p>Abstract</p> <p>Background</p> <p>Partnerships and networking are important for an institution of higher learning like Makerere University College of Health Sciences (MakCHS) to be competitive and sustainable.</p> <p>Methods</p> <p>A stakeholder and sustainability analysis of 25 key informant interviews was conducted among past, current and potential stakeholders of MakCHS to obtain their perspectives and contributions to sustainability of the College in its role to improve health outcomes.</p> <p>Results</p> <p>The College has multiple internal and external stakeholders. Stakeholders from Uganda wanted the College to use its enormous academic capacity to fulfil its vision, take initiative, and be innovative in conducting more research and training relevant to the country’s health needs. Many stakeholders felt that the initiative for collaboration currently came more from the stakeholders than the College. External stakeholders felt that MakCHS was insufficiently marketing itself and not directly engaging the private sector or Parliament. Stakeholders also identified the opportunity for MakCHS to embrace information technology in research, learning and training, and many also wanted MakCHS to start leadership and management training programmes in health systems. The need for MakCHS to be more vigorous in training to enhance professionalism and ethical conduct was also identified.</p> <p>Discussion</p> <p>As a constituent of a public university, MakCHS has relied on public funding, which has been inadequate to fulfill its mission. Broader networking, marketing to mobilize resources, and providing strong leadership and management support to inspire confidence among its current and potential stakeholders will be essential to MakCHS’ further growth. MakCHS’ relevance is hinged on generating research knowledge for solving the country’s contemporary health problems and starting relevant programs and embracing technologies. It should share new knowledge widely through publications and other forms of dissemination. Whether institutional leadership is best in the hands of academicians or professional managers is a debatable matter.</p> <p>Conclusions</p> <p>This study points towards the need for MakCHS and other African public universities to build a broad network of partnerships to strengthen their operations, relevance, and sustainability. Conducting stakeholder and sustainability analyses are instructive toward this end, and have provided information and perspectives on how to make long-range informed choices for success.</p
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