Variable selection in cluster analysis: an approach based on a new index

In cluster analysis, the inclusion of unnecessaryvariables may mask the true group structure. For the selection ofthe best subset of variables, we suggest the use of two overallindices. The first index is a distance between two hierarchicalclusterings and the second one is a similarity index obtained asthe complement to one of the previous distance. Both criteria canbe used for measuring the similarity between clusterings obtainedwith different subsets of variables. An application with a realdata set regarding the economic welfare of the Italian Regionsshows the benefits gained with the suggested procedure

New weighed similarity indexes for market segmentation using categorical variables

In this paper we introduce new similarity indexes forcategorical data with nominal scale. In contrast to traditionallyused similarity measures, they also consider the frequency of themodalities of each attribute in the sample. This feature is usefulwhen dealing with rare categories, since it makes sense todifferently evaluate the pairwise presence of a rare category fromthe pairwise presence of a widespread one. We also propose aspecific weighted index for dependent categorical variables. Thesuitability of the proposed measures from a marketing researchperspective is shown using two real world data sets

Life history differences across a latitudinal gradient in side-blotched lizards (Uta stansburiana)

Latitudinal variation has long been known to affect life history. Bergmann and Allen made latitudinal “rules” for mammalian anatomy and Lack, Skutch, and Moreau described differences in life history in birds. Trade-offs occur between important life history processes, like self maintenance (immunity) and other expensive but necessary processes. It is likely that trade-offs occur mostly when resources are limited. Side-blotched lizards have a wide geographic range, and more northerly lizards have been observed to have longer lifespans than their southern conspecifics. We hypothesized that northern sideblotched lizards would invest more energy into self-maintenance compared to shorter-lived southern animals

Analisis Integrasi Vertikal Pasar Komoditas Cabai Rawit (Capsicum Frutescens L.) di Provinsi Sulawesi Tenggara

This research is motivated by the unequal production of cayenne pepper in all regency cities in Southeast Sulawesi, Resulting in the distribution to some regions that cause price changes that may occur at any time. Changes in the price of cayenne pepper are used by intermediary traders to manipulate prices at the consumer level and at the producer level, the data shows that between 1992 and 2014 there was a difference between the price of cayenne pepper between the consumer market and the producer market. The purpose of this study was to analyze the vertical integration of commodity market of cayenne pepper (Capsicum frutescens L.) in Southeast Sulawesi. This research was conducted in January 2017 until May 2017. The data used are secondary data sourced from Disperindag and BPS in the form of time series data from 1992 to 2014. The analysis method used is Johansen Cointegration and Vector Error Correction Model (VECM). The results show that the vertical market of cayenne pepper between producers and consumers in Southeast Sulawesi has been integrated with the long term, While in the short term there has been no integration of producer and consumer markets. Where price relation occurs only one direction that producer price influence consumer price while consumer price does not influence producer price, If both markets are interconnected then the market is integrated. Based on this, it is expected that the active role of extension agents and farmer groups to provide price information, So that producers, can know the price information that occurs at the consumer level vice versa

Analisis Persediaan Bahan Baku pada Usaha Mete di Kota Kendari (Studi Kasus pada UD. Mete Mubaraq Lombe)

This research aims to know the inventory of raw cashew nuts peeled on UD. Mete Mubaraq Lombe of the year 2017; Analyze the efficiency of the inventory of raw materials according to the EOQ method on UD. Mete Mubaraq Lombe; determine the Safety Stock and Reorder Point at UD. Mete Mubaraq Lombe. The study was designed as a case study of using primary data and secondary data, variables in this study include a Total Inventory Cost, Ordering Cost and Carrying Cost. There were some of the results obtained in this study. First, the type of raw materials used is cashew nuts peeled from Region Lombe by way of partnering. The volume of purchase of raw materials over the past year as many as 52,000 kg. Booking fees during the year 2017 are Rp 43,872,000. Storage costs during the year 2017 are Rp 48,144,000. Secondly, the supply of raw materials of peeled cashew nuts more efficiently by using the EOQ method. It can be seen from the difference in TIC companies issued in the year 2017 is Rp. 45,878,000.4 while the EOQ method based on the TIC of Rp 18,762,434.4. So the difference in TIC is Rp. 27,115,566. Thirdly, in order not to run out of stock in the warehouse, then the safety stock that must always be available in the company as much as 1,459.26 kg and company do a reorder point when the raw materials in the warehouse as much as 1,690.46 kg

Genotoxicity of DrinkingWater Disinfectants in Plant Bioassays

The genotoxicity of two widely used drinking water disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO2), and a new disinfectant, peracetic acid (PAA, CH3-CO-COOH), was evaluated in three short-term plant tests: (1) induction of anaphase chromosome aberrations in the root cells of Allium cepa, (2) micronucleus induction in the root cells of Vicia faba, and (3) micronucleus induction in Tradescantia pollen cells. The study was carried out in the laboratory by directly exposing the plants to several concentrations of the disinfectants in redistilled water at unadjusted (acid) and adjusted (neutral) pHs. Both 0.1 and 0.2 mg/l NaClO induced chromosome aberrations in the Allium cepa test at acid pH, but concentrations up to 0.5 mg/l of all the disinfectants were negative at neutral pH. Concentrations ranging from 0.1 to 0.5 mg/l NaClO, ClO2, and PAA induced micronuclei in Vicia faba at acid pH, while 1–2 mg/l NaClO and ClO2 and 0.5–2 mg/l PAA gave positive responses at neutral pH. Most of concentrations of ClO2 produced positive responses in the Tradescantia micronucleus test. In general, the highest levels of genotoxicity were observed under acid conditions; at acid pH, significant effects were induced by low concentrations of ClO2 and PAA. Since the test concentrations of disinfectants are typical of those encountered in the biocidal treatment of tap water and similar concentrations are consumed daily by a large number of people, the genotoxicity of these compounds may constitute a significant public health concern

An Extensive Questionnaire about Metacognition during Emergency Remote Teaching Involving More Than 3000 Engineering Students

By 11 March 2020, the phrase “COVID-19” had officially entered everyday life across most of the word. Each level of education suddenly faced new changes and new challenges. Emergency remote teaching became widespread, and new methodologies to deliver classes and courses were adopted by educational institutions. In this paper, we focus on the impact of the remote learning experience of engineering students enrolled at the Politecnico di Milano. The subjects were recruited from all engineering courses from the first to the fifth year and were asked to complete a multidimensional survey. The survey featured 66 items regarding the participants’ perceptions of the challenges of emergency remote teaching compared with pre-COVID-19 in-person teaching. The questionnaire addressed six dimensions: the organization of emergency remote teaching, subjective well-being, metacognition, self-efficacy, identity, and socio-demographic information. In this paper, we describe the entire survey and discuss a preliminary analysis. Using Cronbach’s alpha test, a confirmatory factor analysis, and the t-test, we performed a more in-depth analysis concerning the outcomes of metacognition and self-efficacy. The data analysis suggested a small, unexpected change in the metacognition strategies. The students, in some regards, improved their learning strategies. Some other answers underlined their appreciation of the courses’ organization and the lack of relationships with their peers and teachers

Teg® and rotem® traces: Clinical applications of viscoelastic coagulation monitoring in neonatal intensive care unit

The concentration of the majority of hemostatic proteins differs considerably in early life, especially in neonates compared to adulthood. Knowledge of the concept of developmental hemostasis is an essential prerequisite for the proper interpretation of conventional coagulation tests (CCT) and is critical to ensure the optimal diagnosis and treatment of hemorrhagic and thrombotic diseases in neonatal age. Viscoelastic tests (VETs) provide a point-of-care, real-time, global, and dynamic assessment of the mechanical properties of the coagulation system with the examination of both cellular and plasma protein contributions to the initiation, formation, and lysis of clots. In this work, we provide a narrative review of the basic principles of VETs and summarize current evidence regarding the two most studied point-of-care VETs, thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®), in the field of neonatal care. A literature analysis shows that viscoelastic hemostatic monitoring appears to be a useful additive technique to CCT, allowing targeted therapy to be delivered quickly. These tools may allow researchers to determine the neonatal coagulation profile and detect neonatal patients at risk for postoperative bleeding, coagulation abnormalities in neonatal sepsis, and other bleeding events in a timely manner, guiding transfusion therapies using the goal-oriented transfusion algorithm. However, diagnosis and treatment algorithms incorporating VETs for neonatal patients in a variety of clinical situations should be developed and applied to improve clinical outcomes. Further studies should be performed to make routinary diagnostic and therapeutic application possible for the neonatal population

Thrombin Inhibitors from Different Animals

Venous and arterial thromboembolic diseases are still the most frequent causes of death and disability in high-income countries. Clinical anticoagulants are inhibitors of enzymes involved in the coagulation pathway, such as thrombin and factor Xa. Thrombin is a key enzyme of blood coagulation system, activating the platelets, converting the fibrinogen to the fibrin net, and amplifying its self-generation by the activation of factors V, VIII, and XI. Thrombin has long been a target for the development of oral anticoagulants. Furthermore, selective inhibitors of thrombin represent a new class of antithrombotic agents. For these reasons, a number of specific thrombin inhibitors are under evaluation for possible use as antithrombotic drugs. This paper summarizes old and new interests of specific thrombin inhibitors described in different animals