The COVID-19 pandemic and related restrictions led to major transit demand decline for many public transit systems in the United States. This paper is a systematic analysis of the dynamics and dimensions of this unprecedented decline. Using transit demand data derived from a widely used transit navigation app, we fit logistic functions to model the decline in daily demand and derive key parameters: base value, the apparent minimal level of demand and cliff and base points, representing the initial date when transit demand decline began and the final date when the decline rate attenuated. Regression analyses reveal that communities with higher proportions of essential workers, vulnerable populations (African American, Hispanic, Female, and people over 45 years old), and more coronavirus Google searches tend to maintain higher levels of minimal demand during COVID-19. Approximately half of the agencies experienced their decline before the local spread of COVID-19 likely began; most of these are in the US Midwest. Almost no transit systems finished their decline periods before local community spread. We also compare hourly demand profiles for each system before and during COVID-19 using ordinary Procrustes distance analysis. The results show substantial departures from typical weekday hourly demand profiles. Our results provide insights into public transit as an essential service during a pandemic.

The formation and progression of mudulloblastoma (MB) is poorly understood. However, somatic inactivation of pRb/p105, in combination with a somatic or a germ-line TP53 inactivation, leads to MB in a mouse model. Presently, there is no specific evidence of pathway/s alterations for the other two members of the retinoblastoma family, pRb2/p130 and/or p107 in MB. JC virus (JCV) is a human polyomavirus. Although there is no firm evidence that this virus plays a causal role in human neoplasia, it has been clearly proven that JCV is highly oncogenic when injected into the brain of experimental animals. The mechanism of JCV-induced tumorigenesis is not entirely clear. However, several studies relate the oncogenic properties of JCV mainly to its early protein large T-antigen (T-Ag), which is able to bind and inactivate both TP53 and Rb family proteins. Here, we compared the protein expression profiles of p53, p73, pRb family proteins, and PCNA, as main regulators of cell proliferation and death, in different cell lines of mouse primitive neuroectodermal tumors (PNET), either T-Ag-positive or -negative, and in human MB cell lines. Our goal was to determine if changes in the relative expression of these regulators could trigger molecular perturbations underlying MB pathogenesis in mouse and human cells. Our results support that the presence of JCV T-Ag may interfere with the expression of pRb family proteins, specific p73 isoforms, and p53. In turn, this "perturbation" may trigger a network of signals strictly connected with survival and apoptosis. Keywords MEDULLOBLASTOMA; LARGE T-ANTIGEN; JC VIRUS; SV40; pRb FAMILY; p53/p73Embryonal tumors of the central nervous system (CNS) include medulloblastomas (MB), primitive neuroectodermal tumors of the CNS (PNET), and atypical teratoid/rabdoid tumors (ATRT) [Louis et al., 2007]. The mechanism of MB tumorigenesis is poorly understood. Genetic alterations associated with this disease include loss of chromosome p17 and gain of 17q, losses on chromosomes 10q and 11, gains on chromosome 7, and rearrangements of chromosome 1 [Trojanek et al., 2006]. c-Myc and n-Myc amplification, constitutive Sonic hedgehog (SHH) signaling activation, and TP53 pathway alteration have also been reported [Rossi et al., 2008]. TP73 is a member of the p53 family and it has been indicated that overexpression of TP73 isoforms could have a role in the growth and treatment response in Castellino et al., 2007]. pRb/p105, p107, and pRb2/p130 form the retinoblastoma family [Caracciolo et al., 2006;Macaluso et al., 2006]. pRb/p105 mutations are common in several cancers but not in human MB [Giacinti and Giordano, 2006]. However, somatic inactivation of pRb/p105, in combination with a somatic or a germ-line TP53 inactivation, leads to MB in a mouse model. Presently, there is no specific evidence of pRb2/p130 and/or p107 pathway/s alterations in MB, but a role for pRb2/p130 in glioblastoma has been suggested [Pucci et al., 2002].JC virus (JCV) is a human polyomavirus of the polyomaviridae family, which a...

We compare the results of a survey of transit riders during COVID-19 against a regional household travel survey. The Facebook sample over-represents women and car-less respondents compared to the household survey. We also compare the demographics of a subset of Facebook survey respondents, those still riding transit during COVID-19, against a similar survey conducted by Transit app of its users. The picture of post-COVID transit riders is older and of higher incomes in the Facebook sample compared to the Transit app sample. Finally, we replicate a model of vehicle ownership produced with the household travel survey using the Facebook survey.

No abstract