21 research outputs found
Why has research in face recognition progressed so slowly? The importance of variability
Despite many years of research, there has been surprisingly little progress in our understanding of how faces are identified. Here I argue that there are two contributory factors: (a) Our methods have obscured a critical aspect of the problem, within-person variability; and (b) research has tended to conflate familiar and unfamiliar face processing. Examples of procedures for studying variability are given, and a case is made for studying real faces, of the type people recognize every day. I argue that face recognition (specifically identification) may only be understood by adopting new techniques that acknowledge statistical patterns in the visual environment. As a consequence, some of our current methods will need to be abandoned
Human leukocyte antigen alleles associate with COVID-19 vaccine immunogenicity and risk of breakthrough infection
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine immunogenicity varies between individuals, and immune responses correlate with vaccine efficacy. Using data from 1,076 participants enrolled in ChAdOx1 nCov-19 vaccine efficacy trials in the United Kingdom, we found that inter-individual variation in normalized antibody responses against SARS-CoV-2 spike and its receptor-binding domain (RBD) at 28 days after first vaccination shows genome-wide significant association with major histocompatibility complex (MHC) class II alleles. The most statistically significant association with higher levels of anti-RBD antibody was HLA-DQB1*06 (P = 3.2 × 10−9), which we replicated in 1,677 additional vaccinees. Individuals carrying HLA-DQB1*06 alleles were less likely to experience PCR-confirmed breakthrough infection during the ancestral SARS-CoV-2 virus and subsequent Alpha variant waves compared to non-carriers (hazard ratio = 0.63, 0.42–0.93, P = 0.02). We identified a distinct spike-derived peptide that is predicted to bind differentially to HLA-DQB1*06 compared to other similar alleles, and we found evidence of increased spike-specific memory B cell responses in HLA-DQB1*06 carriers at 84 days after first vaccination. Our results demonstrate association of HLA type with Coronavirus Disease 2019 (COVID-19) vaccine antibody response and risk of breakthrough infection, with implications for future vaccine design and implementation
Mesenchymal stem cells in connective tissue engineering and regenerative medicine: Applications in cartilage repair and osteoarthritis therapy
Defects of load-bearing connective tissues
such as articular cartilage, often result from trauma,
degenerative or age-related disease. Osteoarthritis (OA)
presents a major clinical challenge to clinicians due to
the limited inherent repair capacity of articular cartilage.
Articular cartilage defects are increasingly common
among the elderly population causing pain, reduced joint
function and significant disability among affected
patients. The poor capacity for self-repair of chondral
defects has resulted in the development of a large variety
of treatment approaches including Autologous
Chondrocyte Transplantation (ACT), microfracture and
mosaicplasty methods. In ACT, a cartilage biopsy is
taken from the patient and articular chondrocytes are
isolated. The cells are then expanded after several
passages in vitro and used to fill the cartilage defect.
Since its introduction, ACT has become a widely applied
surgical method with good to excellent clinical
outcomes. More recently, classical ACT has been
combined with tissue engineering and implantable
scaffolds for improved results. However, there are still
major problems associated with the ACT technique
which relate mainly to chondrocyte de-differentiation
during the expansion phase in monolayer culture and the
poor integration of the implants into the surrounding
cartilage tissue. Novel approaches using mesenchymal
stem cells (MSCs) as an alternative cell source to patient
derived chondrocytes are currently on trial. MSCs have shown significant potential for chondrogenesis in animal
models. This review article discusses the potential of
MSCs in tissue engineering and regenerative medicine and highlights their potential for cartilage repair and
cell-based therapies for osteoarthritis and a range of
related osteoarticular disorders