Home Gardening Resurgence During COVID: Motivations and Perceived Benefits of Participating in Grow This!

Gardening is associated with a wide array of health benefits. We describe the dissemination of a low-cost social media-based campaign (Grow This!), an intervention intended to reach novice gardeners and which combined elements of old (seeds) and new (Facebook) technology. Grow This! was implemented before (2018, 2019) and during (2020) the COVID pandemic, providing an interesting framework for understanding participants' motivations for gardening. Pre- and post-surveys assessed a variety of topics, including participants' motivations for participating in Grow This!, how they planned to participate, previous gardening experience, the main benefits attributed to participation, and intentions to garden in the future. Descriptive statistics and qualitative analysis were used to analyze the survey data. More than 25,000 people participated in Grow This! over the 3 years, with the majority (77%) participating as a family. Participation in the project spiked during COVID. Primary motivations for participating in Grow This! pre-COVID were education, enjoyment, family engagement, and self-sufficiency; during COVID, motivations remained the same, but shifted in rank. Just over a third of participants were novice gardeners. Participants attributed numerous benefits to their participation, including stress reduction/relaxation, more outdoor time, reduced grocery bills, and eating more fruits and vegetables than normal. A total of 83% of respondents reported being highly likely to have a garden in the future. Home gardening as an intervention is ripe for dissemination, particularly in the aftermath of COVID. Public health professionals can benefit from this understanding of people's motivations to garden and the perceived benefits associated with gardening.

Duration of protection and humoral immunity induced by an adenovirus-vectored subunit vaccine for foot-and-mouth disease (FMD) in Holstein steers.

Foot-and-mouth disease (FMD) is a highly contagious viral infection of cloven hooved animals that continues to cause economic disruption in both endemic countries or when introduced into a formally FMD free country. Vaccines that protect against clinical disease and virus shedding are critical to control FMD. The replication deficient human adenovirus serotype 5 (Ad5) vaccine vector expressing empty FMD virus (FMDV) capsid, AdtFMD, is a promising new vaccine platform. With no shedding or spreading of viral vector detected in field trials, this vaccine is very safe to manufacture, as there is no requirement for high containment faciitites. Here, we describe three studies assessing the proportion of animals protected from clinical vesicular disease (foot lesions) following live-FMDV challenge by intradermolingual inoculation at 6 or 9 months following a single vaccination with the commercial AdtFMD vaccine, provisionally licensed for cattle in the United States. Further, we tested the effect of vaccination route (transdermal, intramuscular, subcutaneous) on clinical outcome and humoral immunity. Results demonstrate that a single dose vaccination in cattle with the commercial vaccine vector expressing capsid proteins of the FMDV strain A24 Cruzeiro (Adt.A24), induced protection against clinical FMD at 6 months (100% transdermal, 80% intramuscular, and 60% subcutaneous) that waned by 9 months post-vaccination (33% transdermal and 20% intramuscular). Post-vaccination serum from immunized cattle (all studies) generally contained FMDV specific neutralizing antibodies by day 14. Anti-FMDV antibody secreting cells are detected in peripheral blood early following vaccination, but are absent after 28 days post-vaccination. Thus, the decay in antibody mediated immunity over time is likely a function of FMDV-specific antibody half-life. These data reveal the short time span of anti-FMDV antibody secreting cells (ASCs) and important performance characteristics of needle-free vaccination with a recombinant vectored subunit vaccine for FMDV.

Replication origin-flanking roadblocks reveal origin-licensing dynamics and altered sequence dependence.

In eukaryotes, DNA replication initiates from multiple origins of replication for timely genome duplication. These sites are selected by origin licensing, during which the core enzyme of the eukaryotic DNA replicative helicase, the Mcm2-7 (minichromosome maintenance) complex, is loaded at each origin. This origin licensing requires loading two Mcm2-7 helicases around origin DNA in a head-to-head orientation. Current models suggest that the origin-recognition complex (ORC) and cell-division cycle 6 (Cdc6) proteins recognize and encircle origin DNA and assemble an Mcm2-7 double-hexamer around adjacent double-stranded DNA. To test this model and assess the location of Mcm2-7 initial loading, we placed DNA-protein roadblocks at defined positions adjacent to the essential ORC-binding site within Saccharomyces cerevisiae origin DNA. Roadblocks were made either by covalent cross-linking of the HpaII methyltransferase to DNA or through binding of a transcription activator-like effector (TALE) protein. Contrary to the sites of Mcm2-7 recruitment being precisely defined, only single roadblocks that inhibited ORC-DNA binding showed helicase loading defects. We observed inhibition of helicase loading without inhibition of ORC-DNA binding only when roadblocks were placed on both sides of the origin to restrict sliding of a helicase-loading intermediate. Consistent with a sliding helicase-loading intermediate, when either one of the flanking roadblocks was eliminated, the remaining roadblock had no effect on helicase loading. Interestingly, either origin-flanking nucleosomes or roadblocks resulted in helicase loading being dependent on an additional origin sequence known to be a weaker ORC-DNA-binding site. Together, our findings support a model in which sliding helicase-loading intermediates increase the flexibility of the DNA sequence requirements for origin licensing.

The dynamics of eukaryotic replication initiation: origin specificity, licensing, and firing at the single-molecule level.

Eukaryotic replication initiation is highly regulated and dynamic. It begins with the origin recognition complex (ORC) binding DNA sites called origins of replication. ORC, together with Cdc6 and Cdt1, mediate pre-replicative complex (pre-RC) assembly by loading a double hexamer of Mcm2-7: the core of the replicative helicase. Here, we use single-molecule imaging to directly visualize Saccharomyces cerevisiae pre-RC assembly and replisome firing in real time. We show that ORC can locate and stably bind origins within large tracts of non-origin DNA and that Cdc6 drives ordered pre-RC assembly. We further show that the dynamics of the ORC-Cdc6 interaction dictate Mcm2-7 loading specificity and that Mcm2-7 double hexamers form preferentially at a native origin sequence. Finally, we demonstrate that single Mcm2-7 hexamers propagate bidirectionally, monotonically, and processively as constituents of active replisomes.

Multiple functions for Mcm2-7 ATPase motifs during replication initiation.

The Mcm2-7 replicative helicase is central to all steps of eukaryotic DNA replication. The hexameric ring of Mcm subunits forms six essential ATPases whose contributions to replication initiation remain unclear. Mcm2-7 complexes containing ATPase-motif mutations showed Mcm2-7 ATP binding and hydrolysis are required for helicase loading. Loading-defective Mcm2-7 mutant complexes were defective in initial Mcm2-7 recruitment or Cdt1 release. Comparison with Cdc6 ATPase mutants showed that Cdc6 ATP hydrolysis is not required for helicase loading but instead drives removal of Mcm2-7 complexes that cannot complete loading. A subset of Mcm2-7 ATPase-site mutants completed helicase loading but could not initiate replication. Individual mutants were defective in distinct events during helicase activation, including maintenance of DNA association, recruitment of the GINS helicase activator, and DNA unwinding. Consistent with its heterohexameric structure, our findings show that the six Mcm2-7 ATPase active sites are specialized for different functions during helicase loading and activation.

Evaluation of dihydrofolate reductase and dihydropteroate synthetase genotypes that confer resistance to sulphadoxine-pyrimethamine in Plasmodium falciparum in Haiti.

BACKGROUND: Malaria caused by Plasmodium falciparum infects roughly 30,000 individuals in Haiti each year. Haiti has used chloroquine (CQ) as a first-line treatment for malaria for many years and as a result there are concerns that malaria parasites may develop resistance to CQ over time. Therefore it is important to prepare for alternative malaria treatment options should CQ resistance develop. In many other malaria-endemic regions, antifolates, particularly pyrimethamine (PYR) and sulphadoxine (SDX) treatment combination (SP), have been used as an alternative when CQ resistance has developed. This study evaluated mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes that confer PYR and SDX resistance, respectively, in P. falciparum to provide baseline data in Haiti. This study is the first comprehensive study to examine PYR and SDX resistance genotypes in P. falciparum in Haiti. METHODS: DNA was extracted from dried blood spots and genotyped for PYR and SDX resistance mutations in P. falciparum using PCR and DNA sequencing methods. Sixty-one samples were genotyped for PYR resistance in codons 51, 59, 108 and 164 of the dhfr gene and 58 samples were genotyped for SDX resistance codons 436, 437, 540 of the dhps gene in P. falciparum. RESULTS: Thirty-three percent (20/61) of the samples carried a mutation at codon 108 (S108N) of the dhfr gene. No mutations in dhfr at codons 51, 59, 164 were observed in any of the samples. In addition, no mutations were observed in dhps at the three codons (436, 437, 540) examined. No significant difference was observed between samples collected in urban vs rural sites (Welch's T-test p-value = 0.53 and permutations p-value = 0.59). CONCLUSION: This study has shown the presence of the S108N mutation in P. falciparum that confers low-level PYR resistance in Haiti. However, the absence of SDX resistance mutations suggests that SP resistance may not be present in Haiti. These results have important implications for ongoing discussions on alternative malaria treatment options in Haiti.

Characterization of an NADH-dependent persulfide reductase from Shewanella loihica PV-4: implications for the mechanism of sulfur respiration via FAD-dependent enzymes.

The NADH-dependent persulfide reductase (Npsr), a recently discovered member of the PNDOR family of flavoproteins that contains both the canonical flavoprotein reductase domain and a rhodanese domain, is proposed to be involved in the dissimilatory reduction of S(0) for Shewanella loihica PV-4. We have previously shown that polysulfide is a substrate for this enzyme, and a recently determined structure of a closely related enzyme (CoADR-Rhod from Bacillus anthracis) suggested the importance of a bound coenzyme A in the mechanism. The work described here shows that the in vivo oxidizing substrates of Npsr are the persulfides of small thiols such as CoA and glutathione. C43S, C531S, and C43,531S mutants were created to determine the role of the flavoprotein domain cysteine (C43) and the rhodanese domain cysteine (C531) in the mechanism. The absolute requirement for C43 in persulfide or DTNB reductase activity shows that this residue is involved in S-S bond breakage. C531 contributes to, but is not required for, catalysis of DTNB reduction, while it is absolutely required for reduction of any persulfide substrates. Titrations of the enzyme with NADH, dithionite, titanium(III), or TCEP demonstrate the presence of a mixed-disulfide between C43 and a tightly bound CoA, and structures of the C43 and C43,531S mutants confirm that this coenzyme A remains tightly bound to the enzyme in the absence of a C43-CoA S-S bond. The structure of Npsr suggests a likely site for binding and reaction with the persulfide substrate on the rhodanese domain. On the basis of kinetic, titration, and structural data, a mechanism for the reduction of persulfides by Npsr is proposed.

Fabrication of silica-coated gold nanorods functionalized with DNA for enhanced surface plasmon resonance imaging biosensing applications.

A novel method for preparing gold nanorods that are first coated with a thin silica film and then functionalized with single-stranded DNA (ssDNA) is presented. Coating the nanorods with 3-5 nm of silica improves their solubility and stability. Amine-modified ssDNA is attached to the silica-coated gold nanorods via a reductive amination reaction with an aldehyde trimethoxysilane monolayer. The nanorods exhibit an intense absorption band at 780 nm, and are used to enhance the sensitivity of surface plasmon resonance imaging (SPRI) measurements on DNA microarrays.

The longitudinal relationship of personality traits and disorders.

Personality disorders are presumed to be stable because of underlying stable and maladaptive personality traits, but while previous research has demonstrated a link between personality traits and personality disorders cross-sectionally, personality disorders and personality traits have not been linked longitudinally. This study explores the extent to which relevant personality traits are stable in individuals diagnosed with 4 personality disorders (schizotypal, borderline, avoidant, and obsessive-compulsive personality disorders) and examines the assumption that these personality disorders are stable by virtue of stable personality traits. This assumption was tested via the estimation of a series of latent longitudinal models that evaluated whether changes in relevant personality traits lead to subsequent changes in personality disorders. In addition to offering large consistency estimates for personality traits and personality disorders, the results demonstrate significant cross-lagged relationships between trait change and later disorder change for 3 of the 4 personality disorders studied.

The representation of four personality disorders by the schedule for nonadaptive and adaptive personality dimensional model of personality.

This study examined the relationships of the Schedule for Nonadaptive and Adaptive Personality (SNAP) model of personality to 4 targeted personality disorders (PDs) in a large multisite sample of patients. Data were examined from 529 patients, who were assigned 1 of 5 primary diagnoses: borderline, schizotypal, avoidant, and obsessive-compulsive PDs and major depression without PD. Patients were administered the SNAP questionnaire and results were compared among diagnostic groups and between patient groups and nonclinical norms. Results indicated that the dimensions of the model appear to have considerable promise in differentiating normal from abnormal personality, particularly in the propensity of individuals with PDs to manifest negative affects and interpersonal detachment. Furthermore, the model appeared to successfully distinguish specific PDs, a property that represents a particular challenge for dimensional models of personality.