OBJECTIVE: we know little about clinical outcomes of arterial calcifications. This study investigates the risk factors of intracranial artery calcifications and its association with cardiovascular disease and cognitive function.
METHODS: patients were recruited from a Dutch memory clinic, between April 2009 and April 2015. The intracranial internal carotid artery (iICA) and basilar artery were analysed on the presence of calcifications. Calcifications in the iICA were also assessed on severity and location in the tunica intima or tunica media. Using logistic regression, risk factors of intracranial artery calcifications were analysed, as well as the association of these calcifications with cardiovascular disease, cognitive function and type of cognitive disorder (including subjective cognitive impairment, mild cognitive impairment and dementia). Cognitive function was assessed with the Cambridge Cognitive Examination.
RESULTS: 1992 patients were included (median age: 78.2 years, ±40% male). The majority of patients had calcifications in the iICA (±95%). Basilar artery calcifications were less prevalent (±8%). Risk factors for cerebral intracranial calcifications were age (p < 0.001), diabetes mellitus (medial iICA, p = 0.004), hypertension (intimal iICA, p < 0.001) and basilar artery, p = 0.019) and smoking (intimal iICA, p = 0.008). iICA calcifications were associated with stroke and intimal calcifications also with myocardial infarction. Intracranial artery calcifications were not associated with cognitive function or type of cognitive disorder.
CONCLUSIONS: the majority of memory clinic patients had intracranial artery calcifications. Cardiovascular risk factors are differentially related to medial or intimal iICA calcifications. iICA calcifications were associated with myocardial infarction and stroke, but not with cognitive outcomes.

Chlorophyll content, one of the most important physiological parameters related to plant photosynthesis, is usually used to predict yield potential. To map the quantitative trait loci (QTLs) underlying the chlorophyll content of rice leaves, a double haploid (DH) population was developed from an indica/japonica (Zhenshan 97/Wuyujing 2) crossing and two backcross populations were established subsequently by backcrossing DH lines with each of their parents. The contents of chlorophyll a and chlorophyll b were determined by using a spectrophotometer to directly measure the leaf chlorophyll extracts. To determine the leaf chlorophyll retention along with maturation, all measurements were performed on the day of heading and were repeated 30 days later. A total of 60 QTLs were resolved for all the traits using these three populations. These QTLs were distributed on 10 rice chromosomes, except chromosomes 5 and 10; the closer the traits, the more clustering of the QTLs residing on common rice chromosomal regions. In general, the majority of QTLs that specify chlorophyll a content also play a role in determining chlorophyll b content. Strangely, chlorophyll content in this study was found mostly to be lacking or to have a negative correlation with yield. In both backcross F1 populations, overdominant (or underdominant) loci were more important than complete or partially dominant loci for main-effect QTLs and epistatic QTLs, thereby supporting previous findings that overdominant effects are the primary genetic basis for depression in inbreeding and heterosis in rice.