Molecular phylogenetics of Melastomataceae and Memecylaceae

Melastomataceae are among the most abundant and diversified groups of plants throughout the tropics, but their intrafamily relationships and morphological evolution are poorly understood. Here we report the results of parsimony and maximum likelihood (ML) analyses of cpDNA sequences from the rbcL and ndhF genes and the rpl16 intron, generated for eight outgroups (Crypteroniaceae, Alzateaceae, Rhynchocalycaceae, Oliniaceae, Penaeaceae, Myrtaceae, and Onagraceae) and 54 species of melastomes. The sample represents 42 of the family’s currently recognized ~150 genera, the 13 traditional tribes, and the three subfamilies, Astronioideae, Melastomatoideae, and Memecyloideae (= Memecylaceae DC.). Parsimony and ML yield congruent topologies that place Memecylaceae as sister to Melastomataceae. Pternandra, a Southeast Asian genus of 15 species of which five were sampled, is the firstbranching Melastomataceae. This placement has low bootstrap support (72%), but agrees with morphological treatments that placed Pternandra in Melastomatacaeae because of its acrodromal leaf venation, usually ranked as a tribe or subfamily. The interxylary phloem islands found in Memecylaceae and Pternandra, but not most other Melastomataceae, likely evolved in parallel because Pternandra resembles Melastomataceae in its other wood characters. A newly discovered plesiomorphic character in Pternandra, also present in Memecylaceae, is a fibrous anther endothecium. Higher Melastomataceae lack an endothecium as do the closest relatives of Melastomataceae and Memecylaceae. The next deepest split is between Astronieae, with anthers opening by slits, and all remaining Melastomataceae, which have anthers opening by pores. Within the latter, several generic groups, corresponding to traditional tribes, receive solid statistical support, but relationships among them, with one exception, are different from anything predicted on the basis of morphological data. Thus, Miconieae and Merianieae are sister groups, and both are sister to a trichotomy of Bertolonieae, Microlicieae + Melastomeae, and Dissochaeteae + Blakeeae. Sonerileae/Oxysporeae are nested within Dissochaeteae, Rhexieae within Melastomeae, and African and Asian Melastomeae within neotropical Melastomeae. These findings have profound implications for our understanding of melastome morphological evolution (and biogeography), implying, for example, that berries evolved from capsules minimally four times, stamen connectives went from dorsally enlarged to basal/ventrally enlarged, and loss of an endothecium preceded poricidal dehiscence

Historical biogeography of Melastomataceae

Melastomataceae and Memecylaceae are pantropically distributed sister groups for which an ndhF gene phylogeny for 91 species in 59 genera is here linked with Eurasian and North American fossils in a molecular clock approach to biogeographical reconstruction. Nine species from the eight next-closest families are used to root phylogenetic trees obtained under maximum likelihood criteria. Melastomataceae comprise ∼3000 species in the neotropics, ∼1000 in tropical Asia, 240 in Africa, and 225 in Madagascar in 150-166 genera, and the taxa sampled come from throughout this geographic range. Based on fossils, ranges of closest relatives, tree topology, and calibrated molecular divergences, Melastomataceae initially diversified in Paloecene/Eocene times in tropical forest north of the Tethys. Their earliest (Eocene) fossils are from northeastern North America, and during the Oligocene and Miocene melastomes occurred in North America as well as throughout Eurasia. They also entered South America, with earliest (Oligocene) South American fossils representing Merianieae. One clade (Melastomeae) reached Africa from the neotropics 14-12 million years ago and from there spread to Madagascar, India, and Indochina. Basalmost Melastomataceae (Kibessieae, Astronieae) are species-poor lineages restricted to Southeast Asia. However, a more derived Asian clade (Sonerileae/Dissochaeteae) repeatedly reached Madagascar and Africa during the Miocene and Pliocene. Contradicting earlier hypotheses, the current distribution of Melastomataceae is thus best explained by Neogene long-distance dispersal, not Gondwana fragmentation

Program for computing partial pressures from residual gas analyzer data

A computer program for determining the partial pressures of various gases from residual-gas-analyzer data is given. The analysis of the ion currents of 18 m/e spectrometer peaks allows the determination of 12 gases simultaneously. Comparison is made to ion-gage readings along with certain other control information. The output data are presented in both tabular and graphical form

A PROPOSAL TO ADOPT FORMULARY APPORTIONMENT FOR CORPORATE INCOME TAXATION: THE HAMILTON PROJECT

The current system of taxing the income of multinational firms in the United States is flawed across multiple dimensions. The system provides an artificial tax incentive to earn income in low-tax countries, rewards aggressive tax planning, and is not compatible with any common metrics of efficiency. The U.S. system is also notoriously complex; observers are nearly unanimous in lamenting the heavy compliance burdens and the impracticality of coherent enforcement. Further, despite a corporate tax rate one standard deviation above that of other OECD countries, the U.S. corporate tax system raises relatively little revenue, due in part to the shifting of income outside the U.S. tax base. In this proposal, we advocate moving to a system of formulary apportionment for taxing the corporate income of multinational firms. Under our proposal, the U.S. tax base for multinational corporations would be calculated based on a fraction of their worldwide income. This fraction would simply be the share of their worldwide sales that occur in the United States. This system is similar to the current method that U.S. states use to allocate national income across states. The state system arose due to the widespread belief that it was impractical to account separately for what income is earned in each state when states are highly integrated economically. Similarly, in an increasingly global world economy, it is difficult to assign profits to individual countries, and attempts to do so are fraught with opportunities for tax avoidance. Under our proposed formulary apportionment system, firms would no longer have an artificial tax incentive to shift income to low-tax locations. This would help protect the U.S. tax base while reducing the distortionary features of the current tax system. In addition, the complexity and administrative burden of the system would be reduced. The proposed system would be both better suited to an integrated world economy and more compatible with the tax policy goals of efficiency, equity, and simplicity

Business Profits (Article 7 OECD Model Convention)

The 2006 OECD Report on attribution of profits to permanent establishments states that its recommendation was not constrained by either the original intent or by the historical practice and interpretation of Article 7. Moreover, the Report recommends a redrafting of both the Article itself and the Commentary. Given this, it seems appropriate to begin by asking: If we were working on a clean slate, what would be the best way to tax MNEs at source in the light of 21st century business practices? The beginning point has to be that a modern MNE does not operate as if its constituent units, either subsidiaries or branches, deal with each other as if they were separate enterprises. Instead, a modern MNE is generally a single, unified enterprise, managed from a central location by managers who are responsible to their shareholders for the results of the MNE as a whole

Business Income (Article 7 OECD MC)

The 2006 OECD Report on attribution of profits to permanent establishments states that its recommendation “was not constrained by either the original intent or by the historical practice and interpretation of Article 7.” Moreover, the Report recommends a redrafting of both the Article itself and the Commentary. Given this, it seems appropriate to begin by asking: If we were working on a clean slate, what would be the best way to tax MNEs at source in the light of 21st century business practices? The beginning point has to be that a modern MNE does not operate as if its constituent units, either subsidiaries or branches, deal with each other as if they were separate enterprises. Instead, a modern MNE is generally a single, unified enterprise, managed from a central location by managers who are responsible to their shareholders for the results of the MNE as a whole

Business Income (Article 7 OECD MC)

The 2006 OECD Report on attribution of profits to permanent establishments states that its recommendation “was not constrained by either the original intent or by the historical practice and interpretation of Article 7.” Moreover, the Report recommends a redrafting of both the Article itself and the Commentary. Given this, it seems appropriate to begin by asking: If we were working on a clean slate, what would be the best way to tax MNEs at source in the light of 21st century business practices? The beginning point has to be that a modern MNE does not operate as if its constituent units, either subsidiaries or branches, deal with each other as if they were separate enterprises. Instead, a modern MNE is generally a single, unified enterprise, managed from a central location by managers who are responsible to their shareholders for the results of the MNE as a whole

Epigenetics and social inequalities in asthma and allergy

Respiratory illnesses, such as asthma and allergy disorders, are disproportionately more common among minority racial/ethnic groups and those of low socioeconomic status. In the United States, asthma prevalence and severity are highest among Puerto Ricans (19.2%), American Indians/Alaska Natives (13%), and Black Americans (12.7%) and higher in families living below the poverty threshold than among those living above it (11% vs 8%–9%).1 Many studies of asthma/allergy inequalities assume that genetic differences underlie racial/ethnic differences in these disorders, pointing to genetic ancestry differences between races, but most genetic variants fail to explain racial/ethnic differences and are usually studied only in White populations.2 In reality, racial and ethnic groups—terms that are often used interchangeably and in overlapping ways—can exhibit varying levels of genetic ancestry, cultural traits, and environmental exposures that all may be entangled together. Thus, any genetic finding differing by race/ethnicity can be confounded by social and environmental factors that also track with different ancestries. However, epigenetic mechanisms (i.e., heritable and stable changes in gene expression) may prove important in explaining these inequalities, as they are influenced by a combination of environmental, social, and genetic factors

Changes in sociocultural stressors, protective factors, and mental health for US Latina mothers in a shifting political climate

Background To investigate changes in sociocultural stressors and protective factors, and mental health in Latina mothers before and after the 2016 Republican presidential nomination. Methods We examined changes in sociocultural stressors, protective factors, and mental health from two prospective cohorts of Latina mothers from interior and border US cities (Nashville, TN, n = 39 and San Diego, CA, ns range = 78–83; 2013–2020). Results We identified significant longitudinal increases in depression, anxiety, and perceived stress in the border city, and reductions in protective factors (e.g., optimism, social support, and familism) across sites. Discrimination varied by location, and was associated with higher stress only at baseline in the border city, and with higher anxiety in the interior city at followup. Acculturative stress was consistently associated with worse mental health across time points in the border city. Various protective factors were associated with reduced stress and anxiety across time points in both cities. Discussion We identified decreased mental health at the border city, and reduced protective factors in Latina mothers across both study sites in the years following the 2016 presidential nomination, during a time of shifting sociopolitical climate. We also identify increased acculturative stress and discrimination over time, particularly at the border city. Interventions to maintain and enhance psychosocial protective factors amongst Latina mothers are warranted