783 research outputs found
Investigating international new product diffusion speed: A semiparametric approach
Global marketing managers are interested in understanding the speed of the
new product diffusion process and how the speed has changed in our ever more
technologically advanced and global marketplace. Understanding the process
allows firms to forecast the expected rate of return on their new products and
develop effective marketing strategies. The most recent major study on this
topic [Marketing Science 21 (2002) 97--114] investigated new product diffusions
in the United States. We expand upon that study in three important ways. (1)
Van den Bulte notes that a similar study is needed in the international
context, especially in developing countries. Our study covers four new product
diffusions across 31 developed and developing nations from 1980--2004. Our
sample accounts for about 80% of the global economic output and 60% of the
global population, allowing us to examine more general phenomena. (2) His model
contains the implicit assumption that the diffusion speed parameter is constant
throughout the diffusion life cycle of a product. Recognizing the likely
effects on the speed parameter of recent changes in the marketplace, we model
the parameter as a semiparametric function, allowing it the flexibility to
change over time. (3) We perform a variable selection to determine that the
number of internet users and the consumer price index are strongly associated
with the speed of diffusion.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS519 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
BERA in the detection of hearing loss in high risk children: an observational study in two tertiary care teaching hospitals in upper Assam region
Background: Significant hearing loss affects children globally (1-3/1,000 infants at birth). Early diagnosis (<6 months age) and subsequent early intervention facilitates normal development of language, regardless of the severity of hearing loss.
Methods: A hospital-based, descriptive, retrospective study was done in two tertiary-care centres of Upper Assam region, upon total (55 + 46 =) 101 high risk children (<15 years) during a study period of 1 year. Patients were subjected to a questionnaire, and hearing tests (BERA/OAE) were performed.
Results: Majority of the cases were <5 years of age, with male preponderance (66.30% cases). NICU graduates with history of ototoxic medications/mechanical ventilation, neonatal hyperbilirubinemia and caregiver concern were the common presenting risk factors identified.
Conclusions: 49.50% cases (n=50) suffered from hearing loss [most common was severe degree of hearing loss, n= 24]. 75% cases in AMCH and 63.6% in LMCH with caregiver concern, 55.55% cases in AMCH and 50% in LMCH with past neonatal hyperbilirubinemia; 50% cases with positive family history; and 46.66% NICU graduates tested positive for hearing loss. Ideally, all high risk children <15 years should be screened for hearing loss with earliest intervention and rehabilitation, to enable them to lead a normal life and reduce the burden of handicap in the community
Extensive intraductal component positive carcinoma of breast: two year study with special reference to ER/PR/HER2NEU/Ki67 in a tertiary care centre of Barak Valley
Background: Extensive intraductal component positive carcinoma (EICPC) of breast is defined by Schnitt et al as-A. 25% or more of Ductal carcinoma in situ (DCIS) is present along the invasive lesion and DCIS is also present outside the area of invasive carcinoma. B. EICPC also include carcinomas in which DCIS is associated with a “small” (approximately 10 mm or less) invasive carcinoma or carcinomas. In Extensive Intraductal Carcinoma (EIDC) most of the cases were associated with recurrence when surgical margin status is not evaluated or focally involved. Our objective was to study the prevalence of EIDC and expression of estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor (HER2NEU)/Ki67(antigen identified by monoclonal antibody KI67) in those cases.Methods: It was a retrospective cross sectional study conducted over a period of 2017 to August 2019.All the histologically confirmed cases of EIDC was retrieved from the institute.Results: Out of 65 cases of invasive carcinoma 17 (26.1%) cases were positive for EICPC. Age of patients ranged from 27 to 73years with mean age of 43 years and 5 patients (29.4%) were postmenopausal. Most of the cases i.e. 6(35.2%) had a ER+/PR+/HER2NEU- status with most of the cases having high 6(47%)Ki-67 index. According to the BLOOM RICHARDSON GRADING 14 cases were grade II (82.3%) and 3 cases were grade I (17.7%) and in pT and pN staging majority were stage pT1 - 7 (41.1%). Most of the cases were mastectomy cases 11 (64.4%) with a base free status except in one lumpectomy case where margin was involved.Conclusions: In this study majority of the cases were ER+//PR+/HER2NEU- with most of the cases having high Ki67 index. Evaluation of EIDC, along with the negative margin status is important to prevent recurrence
Molecular landscape of esophageal cancer: implications for early detection and personalized therapy
Esophageal cancer (EC) is one of the most lethal cancers and a public health concern worldwide, owing to late diagnosis and lack of efficient treatment. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are main histopathological subtypes of EC that show striking differences in geographical distribution, possibly due to differences in exposure to risk factors and lifestyles. ESCC and EAC are distinct diseases in terms of cell of origin, epidemiology, and molecular architecture of tumor cells. Past efforts aimed at translating potential molecular candidates into clinical practice proved to be challenging, underscoring the need for identifying novel candidates for early diagnosis and therapy of EC. Several major international efforts have brought about important advances in identifying molecular landscapes of ESCC and EAC toward understanding molecular mechanisms and critical molecular events driving the progression and pathological features of the disease. In our review, we summarize recent advances in the areas of genomics and epigenomics of ESCC and EAC, their mutational signatures and immunotherapy. We also discuss implications of recent advances in characterizing the genome and epigenome of EC for the discovery of diagnostic/prognostic biomarkers and development of new targets for personalized treatment and prevention
Small intestinal mucosal cells in piglets fed with probiotic and zinc: a qualitative and quantitative microanatomical study
Background: Probiotics and zinc are commonly used and beneficial in pig production. This work aimed to assess the effects of probiotic and zinc on the mucosal cells of the small intestine in respect to digestive capacity and immunity in pre- and post-weaned piglets.Materials and methods: Eighteen Large White Yorkshire piglets were divided equally into control and treatment groups. The piglets were maintained in standard management conditions and were weaned at 28 days of age. The treatment group of piglets fed a mixture of probiotics orally at 1.25 × 109 CFU/day and zinc at 2000 ppm/day from birth to 10 days of age. At three different age-groups viz. day 20 (pre-weaning) and, day 30 and day 60 (post-weaning), the animals were sacrificed. For histomorphology, the tissue samples were processed and stained with Mayer’s haematoxylin and eosin for routine study, combined periodic acid-Schiff-Alcian blue for mucopolysaccharides and Masson-Hamperl argentaffin technique for argentaffin cells. The stained slides were observed under the microscope. The samples were processed as per the standard procedure for scanning and transmission electron microscopy. The statistical analysis of the data using the appropriate statistical tests was also conducted.Results: The mucosal epithelium of villi and crypts were lined by enterocytes, goblet cells, argentaffin cells, microfold (M-cell) cells, tuft cells and intraepithelial lymphocytes. The multipotent stem cells were located at the crypt base. The length of the enterocyte microvilli was significantly longer (p < 0.05) in the treatment group of piglets. The number of different types of goblet cells and argentaffin cells was more in treated piglets irrespective of segments of intestine and age. The intraepithelial lymphocytes were located in apical, nuclear and basal positions in the lining epithelium of both villus tip and base with their significant increase in the treatment group of piglets. The transmission electron microscopy revealed the frequent occurrence of tuft cells in the lining mucosa of the small intestine in treated piglets.Conclusions: Dietary supplementation of probiotic and zinc induced the number of different mucosal cells of villi and crypts in the small intestine that might suggest the greater absorptive capacity of nutrients and effective immunity in critical pre and post-weaned piglets
Dimensional versus cut-off renormalization and the nucleon-nucleon interaction
The role of dimensional regularization is discussed and compared with that of
cut-off regularization in some quantum mechanical problems with ultraviolet
divergence in two and three dimensions with special emphasis on the
nucleon-nucleon interaction. Both types of renormalizations are performed for
attractive divergent one- and two-term separable potentials, a divergent tensor
potential, and the sum of a delta function and its derivatives. We allow
energy-dependent couplings, and determine the form that these couplings should
take if equivalence between the two regularization schemes is to be enforced.
We also perform renormalization of an attractive separable potential superposed
on an analytic divergent potential.Comment: 19 pages + one postscript figur
Assessing blood oxygen level–dependent signal variability as a biomarker of brain injury in sport-related concussion
Mild traumatic brain injury is a complex neurological disorder of significant concern among athletes who play contact sports. Athletes who sustain sport-related concussion typically undergo physical examination and neurocognitive evaluation to determine injury severity and return-to-play status. However, traumatic disruption to neurometabolic processes can occur with minimal detectable anatomic pathology or neurocognitive alteration, increasing the risk that athletes may be cleared for return-to-play during a vulnerable period and receive a repetitive injury. This underscores the need for sensitive functional neuroimaging methods to detect altered cerebral physiology in concussed athletes. The present study compared the efficacy of Immediate Post-concussion Assessment and Cognitive Testing composite scores and whole-brain measures of blood oxygen level–dependent signal variability for classifying concussion status and predicting concussion symptomatology in healthy, concussed and repetitively concussed athletes, assessing blood oxygen level–dependent signal variability as a potential diagnostic tool for characterizing functional alterations to cerebral physiology and assisting in the detection of sport-related concussion. We observed significant differences in regional blood oxygen level– dependent signal variability measures for concussed athletes but did not observe significant differences in Immediate Post-concussion Assessment and Cognitive Testing scores of concussed athletes. We further demonstrate that incorporating measures of functional brain alteration alongside Immediate Post-concussion Assessment and Cognitive Testing scores enhances the sensitivity and specificity of supervised random forest machine learning methods when classifying and predicting concussion status and post-concussion symptoms, suggesting that alterations to cerebrovascular status characterize unique variance that may aid in the detection of sport-related concussion and repetitive mild traumatic brain injury. These results indicate that altered blood oxygen level–dependent variability holds promise as a novel neurobiological marker for detecting alterations in cerebral perfusion and neuronal functioning in sport-related concussion, motivating future research to establish and validate clinical assessment protocols that can incorporate advanced neuroimaging methods to characterize altered cerebral physiology following mild traumatic brain injury
Solving Global Optimization Problems Using MANGO
Traditional approaches for solving global optimization problems generally rely on a single algorithm. The algorithm may be hybrid or applied in parallel. Contrary to traditional approaches, this paper proposes to form teams of algorithms to tackle global optimization problems. Each algorithm is embodied and ran by a software agent. Agents exist in a multiagent system and communicate over Our proposed MultiAgent ENvironment for Global Optimization (MANGO). Through Communication and cooperation, the agents complement each other in tasks that they cannot do on their own. This paper gives a formal description of MANGO and Outlines design principles for developing agents to execute Oil MANGO. Our case study shows the effectiveness of multiagent teams in solving global optimization problems
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