538 research outputs found
Biotecnologia: concepção e validação de trabalhos práticos
Doutoramento em BiologiaÉ hoje geralmente aceite que a educação em ciências, além da aprendizagem
de conhecimento conceptual e procedimental, deve promover nos alunos o
desenvolvimento de competências investigativas, ou seja, competências para
identificar, formular e resolver problemas. Porém, o desenvolvimento de
actividades práticas de natureza investigativa é difícil, pela carência, ou
mesmo ausência, de vivências dos professores em investigações, sobretudo
em projectos aplicáveis nas práticas lectivas. A frequente falta de formação
inicial e contínua dos professores de ciências, relativamente ao
desenvolvimento de competências indispensáveis à implementação desta
perspectiva de trabalho prático, constitui um obstáculo à concretização de
inovações educativas preconizadas para a educação em ciências, referidas em
documentos aprovados e publicados pelo Ministério da Educação, em
particular, orientações curriculares e programas disciplinares.
A abordagem de temáticas em biotecnologia configura-se como uma
necessidade das sociedades actuais, de modo que, atendendo aos avanços
que se têm vindo a verificar nesta área, deverá integrar-se em educação
científica formal, relacionando-a com a vida quotidiana dos cidadãos. Além de
componentes científicas inovadoras, os seus desenvolvimentos têm diversas
implicações, designadamente éticas, políticas, económicas e sociais.
A investigação apresentada nesta dissertação insere-se neste quadro, a qual
se baseou no seguinte problema: “Partindo de temáticas em biotecnologia,
como estimular o desenvolvimento de trabalho prático numa perspectiva
investigativa por professores de Biologia e/ou Geologia?”. Definiram-se dois
objectivos gerais: 1) testar, conceber e optimizar actividades laboratoriais e
experimentais em biotecnologia, transponíveis para contextos educativos dos
ensinos básico e secundário, desmistificando a complexidade associada ao
trabalho prático nesta área; 2) conceber, implementar e avaliar uma acção de
formação para professores de Biologia e/ou Geologia, na modalidade de
Oficina de Formação, visando em contextos escolares e em temáticas de
biotecnologia, desenvolver percursos investigativos.
A acção de formação “Desenvolvimento de actividades práticas em
biotecnologia numa perspectiva investigativa: um contributo na (re)orientação
de ensino e aprendizagem de ciências” estimulou os professores-formandos a
participarem activamente num programa que integrava abordagens inovadoras
de trabalho prático, e criou condições para, com orientação e apoio,
desenvolverem percursos investigativos a partir de situações-problema em
temáticas de biotecnologia.
Na generalidade, as reflexões dos professores-formandos sobre os percursos
investigativos planeados e implementados, e os ganhos a nível profissional
e/ou pessoal, além de referências elogiosas à estrutura e sequência das
actividades propostas na formação, realçaram os seguintes aspectos positivos:
a) o enriquecimento de conhecimentos científico-tecnológicos em
biotecnologia; b) a oportunidade de reflexão sobre as suas práticas e a
necessidade de uma nova forma de olhar para o trabalho laboratorial e
experimental e para o seu papel nas aulas de ciências; c) as potencialidades
de trabalho prático numa perspectiva investigativa em termos de mobilização
de competências de natureza conceptual e processual; d) o desenvolvimento
de competências técnicas e processuais necessárias à implementação de
percursos investigativos com recurso a procedimentos em biotecnologia.
Do presente estudo decorrem implicações educacionais que se esperam
pertinentes para a formação de professores de ciências e elaboração de
recursos didácticos, designadamente manuais escolares, assim como, para a
gestão dos programas disciplinares. Este estudo permitiu, ainda, apresentar
propostas para futuras investigações.It is currently recognised that science education, besides providing the learning
of conceptual and procedural knowledge, must endorse in the students the
development of research competences, i.e., the competences to identify,
formulate and solve problems. However, the development of practical activities
of research nature are difficult, by the shortage, or even absence, of teachers’
experiences in research, mostly in projects applicable to teaching practices.
The recurrent lack of initial and continuing training of science teachers, for the
development of skills needed to implement this perspective of practical work, is
an obstacle to the implementation of educational innovations promoted for
science education, and reported in documents published by the Ministry of
Education, in particular, in curricular guidelines and in disciplinary programs.
Approaching themes in biotechnology seems to be a necessity of modern
society, so that, given the advances that have been observed in this field, it
shall be integrated into formal scientific education, and be connected with the
everyday lives of citizens. In addition to innovative scientific components, its
exploitation has several implications, namely ethical, political, economic and
social ones.
The investigation presented in this thesis fits into this framework, which was
based on the following problem: "Using the thematic of biotechnology, how to
stimulate the development of practical work within an investigative perspective
for teachers of biology and/or geology?". We defined two general objectives: 1)
to test, design and optimize laboratorial and experimental activities in
biotechnology, transferable to educational contexts of primary and secondary
education, demystifying the complexities associated with practical work in this
area; 2) to design, implement and evaluate a training action for teachers of
biology and/or geology, in the form of training workshop, aiming at developing
investigative pathways, in school contexts and using themes of biotechnology.
The training action "Development of practical activities in biotechnology within
an investigative perspective: a contribute to the (re)orientation of teaching and
learning in sciences" encouraged teachers to participate actively in a program
that integrated innovative approaches into practical work, and created
conditions in order to, with guidance and support, develop investigative
pathways using problem-situations in biotechnology issues.
Overall, the teachers reflected on: the planned and implemented investigative
pathways; the incomes at a professional and/or personnel levels. These
reflections and the positive references to the structure and sequence of the
proposed activities highlighted the following aspects: a) the enrichment of
scientific and technological knowledge in biotechnology; b) the opportunity to
reflect on their practices and the need for a new way of looking at the
laboratorial and experimental work and their role in science classes; c) the
potential for practical work in an investigative perspective in terms of
mobilization of expertise; d) the development of measures to implement
investigative routes using procedures in biotechnology.
From the present study educational implications emerged that one hopes to be
appropriate to the training of science teachers and to the elaboration of
teaching resources, including scholar manuals, as well as for the management
of course programs. This study also allowed to present proposals for future
research
Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era
The LHCb Upgrade II will fully exploit the flavour-physics opportunities of the HL-LHC, and study additional physics topics that take advantage of the forward acceptance of the LHCb spectrometer. The LHCb Upgrade I will begin operation in 2020. Consolidation will occur, and modest enhancements of the Upgrade I detector will be installed, in Long Shutdown 3 of the LHC (2025) and these are discussed here. The main Upgrade II detector will be installed in long shutdown 4 of the LHC (2030) and will build on the strengths of the current LHCb experiment and the Upgrade I. It will operate at a luminosity up to 2×1034
cm−2s−1, ten times that of the Upgrade I detector. New detector components will improve the intrinsic performance of the experiment in certain key areas. An Expression Of Interest proposing Upgrade II was submitted in February 2017. The physics case for the Upgrade II is presented here in more depth. CP-violating phases will be measured with precisions unattainable at any other envisaged facility. The experiment will probe b → sl+l−and b → dl+l− transitions in both muon and electron decays in modes not accessible at Upgrade I. Minimal flavour violation will be tested with a precision measurement of the ratio of B(B0 → μ+μ−)/B(Bs → μ+μ−). Probing charm CP violation at the 10−5 level may result in its long sought discovery. Major advances in hadron spectroscopy will be possible, which will be powerful probes of low energy QCD. Upgrade II potentially will have the highest sensitivity of all the LHC experiments on the Higgs to charm-quark couplings. Generically, the new physics mass scale probed, for fixed couplings, will almost double compared with the pre-HL-LHC era; this extended reach for flavour physics is similar to that which would be achieved by the HE-LHC proposal for the energy frontier
LHCb upgrade software and computing : technical design report
This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
O ensino de genética e bioquímica nas escolas: concepção de protocolos para aplicação prática nas aulas
Mestrado em Ensino de Geologia e BiologiaA Biologia, apesar de ser uma ciência secular, encontra-se em evolução
vertiginosa, sendo não só uma das ciências que mais evoluiu no século que
agora terminou, como é por vezes apontada como a que mais influenciará as
próximas gerações.
O ensino de novos campos da Biologia nas escolas é hoje um requisito
indispensável face aos avanços que esta área do conhecimento tem vindo a
sofrer nos últimos anos. O entendimento de novos campos da Biologia passa,
obrigatoriamente, pelo ensino de Genética Molecular e de Bioquímica, uma
vez que a célula como unidade estrutural e funcional de todos os seres vivos
não se limita a características estruturais e funcionais, revela-se também a
nível molecular.
O presente estudo visa sobretudo dar uma visão inovadora no que se refere à
implementação no ensino secundário de novas actividades laboratoriais em
áreas actuais de Biologia. Deste modo, pretende-se desmistificar a
complexidade da Biologia Molecular e demonstrar que é possível realizar nos
laboratórios escolares actividades inovadoras.
Este trabalho de investigação foi dividido em duas partes. A primeira parte teve
como objectivos adaptar/conceber, implementar e avaliar novos protocolos na
área de Genética Molecular e Bioquímica, no âmbito do Ensino Experimental
das Ciências. Nesta parte do trabalho os protocolos que foram objecto de
estudo foram: “Extracção de DNA de células vegetais” e a “Quantificação de
proteínas em alimentos pelo método de Lowry”. Estas actividades laboratoriais
foram realizadas por um grupo de 47 alunos do 11º Ano da Escola Secundária
D. Inês de Castro de Alcobaça, nas aulas de Ciências da Terra e da Vida. A
avaliação do impacto destas actividades laboratoriais foi efectuada através da
aplicação de um questionário – “Questionário de opiniões”.
Os resultados obtidos mostraram que estas actividades influenciaram
sobretudo as competências no domínio afectivo, tendo contribuído,
fundamentalmente para tornar mais reais os fenómenos biológicos, para além
de despertarem o interesse pela Ciência em geral e pela Biologia em
particular.
A segunda parte deste trabalho teve como objectivo efectuar o diagnóstico do
interesse dos alunos pela realização de diversas actividades laboratoriais.
Para o efeito foi aplicado um questionário a turmas do 11º Ano de Ciências da
Terra e da Vida, em escolas dos distritos de Aveiro, Coimbra, Porto e Viseu,
com um total de 160 inquiridos. Os resultados deste questionário mostraram
que as actividades laboratoriais avaliadas com maior interesse pelos inquiridos
foram: a “clonagem de plantas: cultura in vitro”, a “extracção de DNA” e a
“observação de células em divisão (mitose e meiose)”.In spite of Biology being a secular science has very quick development in order
to become one of the most developed sciences in this last century, being
sometimes mentioned as the one that will influence the next generation.
The teaching of new subjects of Biology in schools is today an essential
requirement to face the progress that this area of knowledge has suffered in the
last years. The understanding of the new subjects of Biology includes the
obligatory teaching of Molecular Genetics and Biochemistry, because the cells
as structural and functional unit of all live beings is not only limited to structural
and functional characteristics, but is also on a molecular level.
The actual learning aim mainly to give a new vision putting into practice in the
secondary education, innovative laboratorial activities in current areas of
Biology. Therefore the intention is to show that Molecular Biology is not
complex and that it is possible to do innovative activities in the school
laboratories.
This research work was divided in two parts. The objectives of the first part
were to adapt/conceive, fulfil and evaluate new protocols in the area of
Molecular Genetics and Biochemistry fields. In this part of the work the
protocols that were part of the learning were: “Extraction of DNA of plant cells”
and “Quantification of food proteins by Lowry’s method”. These laboratorial
activities were done by a group of 47 students from the 11th degree of the
Alcobaça Secondary School D. Inês de Castro, in the classes of Earth and Life
Sciences. The impact of appreciation of these laboratorial activities was made
by using a questionary – “Questionary of opinions “.
The results obtained in this study showed that the above mentioned activities
influenced, especially, capacities on the affective domain. This has contributed,
fundamentally, towards making Biological phenomenon’s more realistic and to
help the interest for Science in general and for Biology in particular.
The aim of the second part of the work was to determine the interest of the
students in different laboratory activities. For that purpose a questionary was
given to students of 11th degree of Earth and Life Sciences, in the schools of
the districts of Aveiro, Coimbra, Porto e Viseu, with a total of 160 inquiries. The
results of this questionary showed that the activities preferred by the students
were: the “cloning of plants: culture in vitro”, the “extraction of DNA” and the
“observation of the division of the cells (mitosis and meiosis)
- …