Weak relationships between leaf phenology and isohydric and anisohydric behavior in lowland wet tropical forest trees

Wet tropical forest trees display a wide range of leaf phenology dynamics. However, the interrelation between deciduousness, water status, and leaf and stem characteristics have been poorly investigated compared with dry forests. We studied wet forest trees to answer the following questions: (1) do water regulation modes (iso/anisohydric behavior) of evergreen species differ from those found in deciduous species? (2) Does leaf water potential (Ψ_L) influences leaffall and emergence dynamics? (3) Are leaf and stem characteristics consistent across evergreen and deciduous trees? We evaluated vegetative phenology, Ψ_L, and leaf and stem characteristics of six evergreen and three deciduous species monthly for 2 yr. Species exhibited different leaffall and emergence dynamics, as well as different water regulation modes, independent of their deciduousness. Thus, the relationship between leaf phenology and water regulation behaviors appears to be a species‐specific property rather than a functional group attribute. Ψ_L had no direct influence on the dynamics of leaffall and/or emergence, indicating that this process is not modulated by water availability alone. Individual groups of evergreen and deciduous species could not be identified using principal component analysis (PCA), but a decoupling was observed in the leaf and stem economics spectra. The lack of an interrelation between deciduousness and iso/anisohydry, as well as the independence of leaf and stem trade‐offs, emphasizes that more systematic measurements of vegetative phenology and ecophysiological characteristics are necessary to advance our knowledge of leaf habit and water regulation behaviors based on the functional traits of wet forest plants.     

Population estimates of the breeding birds of the Tinhosas islands (Gulf of Guinea), the only major seabird colony of the eastern tropical Atlantic

The Tinhosas islands, in São Tomé e Príncipe, host the most important seabird breeding colony in the Gulf of Guinea, but information on its conservation status was hitherto unpublished or anecdotal, the last assessment having been performed in 1997. A two-day expedition to the Tinhosas islands was undertaken to estimate the status of breeding seabirds in 2013. Four of the five seabird species known to breed in São Tomé e Príncipe, namely Brown Booby Sula leucogaster, Sooty Tern Onychoprion fuscatus, Brown Noddy Anous stolidus and Black Noddy Anous minutus, occur on the Tinhosas. A decrease of 80% in Brown Booby numbers, possibly due to occasional exploitation, and a 30% increase in Sooty Tern and Black Noddy numbers, were found compared to 1997 data although survey methods differed. Breeding of Brown Noddy and Madeiran Storm-petrel Hydrobates castro remains unconfirmed. Our estimates confirmed that BirdLife International Important Bird and Biodiversity Area criteria are met for at least one species, the Sooty Tern. The islands are not legally protected, nonetheless, apart from moderate levels of disturbance by fishermen who land on Tinhosa Grande, no alien species were seen, and no immediate threats to the Tinhosas colony were detected. Multiple visits within and between years are recommended, to census breeders, monitor threats and establish breeding phenologies.     

A panel of recombinant proteins for the serodiagnosis of caseous lymphadenitis in goats and sheep

Caseous lymphadenitis (CLA) is a small ruminant disease characterized by the development of granulomatous lesions in superficial and internal lymph nodes, as well as in some organs, and causes significant economic losses worldwide. The aetiological agent of CLA is the bacterium Corynebacterium pseudotuberculosis; however, the commercially available diagnostic tools present problems with regard to specificity, which can lead to false-negative results. This study aimed to develop an indirect enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulins in goats and sheep using recombinant C. pseudotuberculosis PLD, CP40, PknG, DtxR and Grx proteins. For validation of the ELISAs, 130 goat serum samples and 160 sheep serum samples were used. The best ELISA for goats was developed using a combination of PLD and CP40 as antigens at a 1:1 ratio, which presented 96.9% sensitivity and 98.4% specificity. The most effective ELISA for sheep presented 91% sensitivity and 98.7% specificity when recombinant PLD alone was used as the antigen. These ELISAs can be used as highly accurate tools in epidemiological surveys and for the serodiagnosis of C. pseudotuberculosis infection in goats and sheep.     

Minimizing the Influence of Fluorescent Tags on IgG Partition in PEG–Salt Aqueous Two‐Phase Systems for Rapid Screening Applications

Aqueous two‐phase extraction (ATPE) has been showing significant potential in the biopharmaceutical industry, allowing the selective separation of high‐value proteins directly from unclarified cell culture supernatants. In this context, effective high‐throughput screening tools are critical to perform a rapid empirical optimization of operating conditions. In particular, microfluidic ATPE screening devices, coupled with fluorescence microscopy to continuously monitor the partition of fluorophore‐labeled proteins, have been recently demonstrated to provide short diffusion distances and rapid partition, using minimal reagent volumes. Nevertheless, the currently overlooked influence of the labeling procedure on partition must be carefully evaluated to validate the extrapolation of results to the unlabeled molecule. Here, three fluorophores with different global charge and reactivity selected to label immunoglobulin G (IgG) at degrees of labeling (DoL) ranging from 0.5 to 7.6. Labeling with BODIPY FL maleimide (DoL = 0.5), combined with tris(2‐carboxyethyl) phosphine (TCEP) to generate free thiol groups, is the most promising strategy to minimize the influence of the fluorophore on partition. In particular, the partition coefficient (K_p) measured in polyethylene glycol (PEG) 3350–phosphate systems with and without the addition of NaCl using microtubes (batch) or microfluidic devices (continuous) is comparable to those quantified for the native protein.     

Different ways to die in a changing world: Consequences of climate change for tree species performance and survival through an ecophysiological perspective

Anthropogenic activities such as uncontrolled deforestation and increasing greenhouse gas emissions are responsible for triggering a series of environmental imbalances that affect the Earth's complex climate dynamics. As a consequence of these changes, several climate models forecast an intensification of extreme weather events over the upcoming decades, including heat waves and increasingly severe drought and flood episodes. The occurrence of such extreme weather will prompt profound changes in several plant communities, resulting in massive forest dieback events that can trigger a massive loss of biodiversity in several biomes worldwide. Despite the gravity of the situation, our knowledge regarding how extreme weather events can undermine the performance, survival, and distribution of forest species remains very fragmented. Therefore, the present review aimed to provide a broad and integrated perspective of the main biochemical, physiological, and morpho‐anatomical disorders that may compromise the performance and survival of forest species exposed to climate change factors, particularly drought, flooding, and global warming. In addition, we also discuss the controversial effects of high CO₂ concentrations in enhancing plant growth and reducing the deleterious effects of some extreme climatic events. We conclude with a discussion about the possible effects that the factors associated with the climate change might have on species distribution and forest composition.