A novel post-1950 CE atmospheric C record for the tropics using absolutely dated tree rings in the equatorial Amazon.

In this study, we present a comprehensive atmospheric radiocarbon (C) record spanning from 1940 to 2016, derived from 77 single tree rings of Cedrela odorata located in the Eastern Amazon Basin (EAB). This record, comprising 175 high-precision C measurements obtained through accelerator mass spectrometry (AMS), offers a detailed chronology of post-1950 CE (Common Era) C fluctuations in the Tropical Low-Pressure Belt (TLPB). To ensure accuracy and reliability, we included C-AMS results from intra-annual successive cuts of the tree rings associated to the calendar years 1962 and 1963 and conducted interlaboratory comparisons.

Radiocarbon and wood anatomy as complementary tools for generating tree-ring records in Bolivia.

The science of tropical dendrochronology is now emerging in regions where tree-ring dating had previously not been considered possible. Here, we combine wood anatomical microsectioning techniques and radiocarbon analysis to produce the first tree-ring chronology with verified annual periodicity for a new dendrochronological species, (commonly known as "algarrobo blanco") in the tropical Andes of Bolivia. First, we generated a preliminary chronology composed of six trees using traditional dendrochronological methods (i.

High-precision C measurements of parenchyma-rich Hymenolobium petraeum tree species confirm bomb-peak atmospheric levels and reveal local fossil-fuel CO emissions in the Central Amazon.

Atmospheric radiocarbon (C) recorded in tree rings has been widely used for atmospheric C calibration purposes and climate studies. But atmospheric C records have been limited along tropical latitudes. Here we report a sequence from 1938 to 2007 of precisely measured C dates in tree rings of the parenchyma-rich Hymenolobium petraeum tree species (Porto Trombetas, 1°S, 56°W) from the Central Brazilian Amazon.

Emotional and behavioural problems in children and adolescents with primary headache.

Psychiatric co-morbidity is an important risk factor for chronification of primary headache into adulthood. The aim of this study was to investigate the extent and clinical relevance of emotional and behavioural problems in children and adolescents with primary headache. Children and adolescents (n = 128) with primary headache (International Headache Society, codes 1.

Olfactory and trigeminal event-related potentials in migraine.

Background: Trigeminal/neuronal hyperexcitability and spreading depression activating the trigemino-vascular system are discussed in migraine-pathophysiology. This study investigated trigeminal and olfactory event-related potentials in migraineurs.

Methods: Nasal chemosensitivity was assessed in 19 female migraineurs with or without aura > 72 h before or after an attack and in 19 healthy females employing event-related cortical potentials (ERPs) after specific trigeminal stimulation of nasal nociceptors with short pulses of CO2, and specific olfactory stimulation with H2S.